Biomedical subjects

H Kolk

Publications and source records attributed to H Kolk.

12 recordsLinked to original sources

PubMed2002

Prevalence of antibiotic resistance of Helicobacter pylori isolates in Estonia during 1995-2000 in comparison to the consumption of antibiotics used in treatment regimens.

OBJECTIVE: To find a possible relation between the dynamics of antibiotic resistance of Helicobacter pylori isolates and the consumption of antibiotics during the last several years in Estonia. METHODS: Helicobacter pylori isolates were collected from the gastric mucosa of patients with peptic ulcer (153) and gastritis (68) and isolated on the Columbia Agar Base. From 1995 to 1997 the disk-diffusion method was used for testing of H. pylori susceptibility to metronidazole (115 isolates), erythromycin (119 isolates), tetracycline (119 isolates) and amoxicillin (119 isolates). From 1998 to 2000 the susceptibility of H. pylori to metronidazole (106 isolates), amoxicillin (30 isolates), clarithromycin (106 isolates) and ciprofloxacin (30 isolates) was assessed by E tests. Data from the Estonian State Agency of Medicines were used to determine the antibiotic consumption rate. RESULTS: Up to the year 2000 all the investigated H. pylori isolates were susceptible to ciprofloxacin; the resistance to clarithromycin, tetracycline, amoxicillin and erythromycin was 3%, 1.7%, 0.7% and 2.5%, respectively. Forty-six percent of H. pylori isolates were resistant to metronidazole. During 1995-2000 the consumption of amoxicillin, erythromycin and ciprofloxacin increased and the consumption of tetracycline decreased. The increasing consumption of amoxicillin reached a level 5.7 times than that of the consistent use of metronidazole. The resistance to amoxicillin appeared to be very low and resistance to metronidazole was continuously high. The increase of clarithromycin consumption (from 0.002 to 1.119 defined daily doses/1000) during three years was associated with the appearance of the first clarithromycin-resistant isolates in 2000. CONCLUSION: No relation was observed between the antibiotic consumption rate and the resistance pattern of H. pylori to metronidazole, amoxicillin, erythromycin, tetracycline and ciprofloxacin during recent years among the in population.

Adult↗

PubMed2001

Does agrammatic speech constitute a regression to child language? A three-way comparison between agrammatic, child, and normal ellipsis.

When children are in the process of learning their mother tongue, they show frequent use of nonfinite clauses, even though they produce finite clauses at the same time, thereby demonstrating the availability of the functional domain associated with finiteness. In this study the hypothesis was tested that this behavior results from an overuse of the normal elliptical repertoire that has also been observed in agrammatic aphasia. The purpose of this overuse is prevention of computational overload. In support of the hypothesis it was found that children behaved very similar to aphasics and normal adults with respect to the following parameters: (a) distribution of types of ellipsis, (b) elaboration of ellipses, (c) word order, (d) subject omission, (e) frequency of weak subject pronouns, and (f) verb type (eventivity). The results also support the Jackson/Jakobson regression hypothesis, at least at the grammatical level.

Adult↗

PubMed2001

Health status of the older population in Estonia.

AIM: To assess the prevalence of physical, depressive, and cognitive disorders in the elderly population in Estonia. METHODS: The prevalence of various common morbidities was determined by a questionnaire sent to 200 general practitioners (GP). GPs were asked to collect data, use medical records, and interview five randomly selected patients (a total of 1,000 people aged 65 years or older). Physical morbidities of older persons were assessed according to their self-reports and reports of their general practitioners. Depressive symptoms and cognitive status were determined by 15-item Geriatric Depression Scale and Mini Mental State Examination, respectively. Response rate was 81%. RESULTS: The prevalences of diseases were as follows: hypertension 63.2%, arthritis 61.3%, ischemic heart disease 56.5% (history of myocardial infarction, 9.8%), heart failure 41.4%, heart rhythm disorders 37.5%, hypercholesterolemia 25.4%, kidney and/or urinary disorders 20.5%, osteoporosis 15.5%, diabetes mellitus 14.9%, chronic airway diseases 13.8% (emphysema 5.8%, asthma 5.5%), hypotension 11.1%, gastroduodenal peptic ulcers 10.6%, thyroid diseases 8.9%, malignant tumors 8.1%, psychiatric disorders 5.7%, and stroke 5.3%. Depressive symptoms were found in 40.3% and cognitive impairment in 22.5% of the elderly persons. CONCLUSIONS: The general structure of diseases in the Estonian elderly population is similar to that of other European countries, but the prevalence of cardiovascular, depressive, and cognitive disorders is much higher.

Aged↗

PubMed2000

Metronidazole and clarithromycin susceptibility and the subtypes of vacA of Helicobacter pylori isolates in Estonia.

The prevalence of metronidazole and clarithromycin resistance of Helicobacter pylori strains under different growth conditions (microaerophilic or anaerobic preincubation) was tested in 56 patients suffering from gastritis and peptic ulcer. vacA subtypes were detected in 46 H. pylori strains and were subsequently compared with the antibiotic resistance pattern. From 56 isolates, 26 proved resistant and 30 sensitive to metronidazole. The patients with peptic ulcer and gastritis were infected with both metronidazole-sensitive and metronidazole-resistant strains. In anaerobic preincubation all the strains were sensitive to metronidazole (MIC < 8 mg/l). All the strains were clarithromycin-sensitive (MIC < 2 mg/l). In the patients with gastritis and peptic ulcer s1 was the predominant vacA subtype. Comparison of vacA subtypes with the diagnoses revealed no correlation; different virulence factors such as vacA subtypes and antibiotic resistance to metronidazole in a microaerophilic milieu proved unrelated.

Adolescent↗

PubMed1999

Accidental fenitrothion intoxication in young broilers.

Death from fenitrothion intoxication in young broiler chicks has never been reported. The mortality in this instance was 16.4% in the first week. The dead birds were found lying in a ventral position resting their heads on the floor. Prior to death dyspnea and paralysis occurred. A concentration of 120 mg fenitrothion/kg of litter (dry weight) was found.

Animals↗

PubMed1996

Judgments of semantic anomaly in agrammatic patients: argument movement, syntactic complexity, and the use of heuristics.

Two studies on the judgment of semantic anomaly of sentences in agrammatic aphasia are reported. The primary question was whether performance on this task would be negatively affected by sentence complexity. In a first experiment, we repeated part of the study by Schwartz, Linebarger, Saffran, and Pate (Language and Cognitive Processing, 2, 85-113, 1987). With a group of 15 Dutch-speaking agrammatics, we obtained a small but significant negative effect of "lexical padding": sentences like "#the puppy ran around excitedly and accidently dropped the little boy onto the wet grass which upset Louise" elicited more errors than their simple counterparts, "#the puppy dropped the little boy." In our second study, we looked at (a) the effect of sentence embedding (e.g., "the doctor, who was tired of climbing a staircase, examined the patient") and (b) the effect of incorporating a "distractor agent" in the sentences, that is, an NP that could serve as a possible agent of the critical action (e.g., "the doctor, who had talked to the nurse, examined the patient"). In addition we employed sentences with moved arguments (e.g., "it was the patient who the doctor examined"). There were two major conclusions. First, syntactic complexity has a strong negative effect on anomaly judgments. Second, patient use a linear-order strategy to deal with the task. Results are discussed in terms of a range of recent approaches to agrammatic comprehension, not only representational hypotheses, based upon linguistic theory, but also processing accounts.

Aged↗

PubMed1995

A time-based approach to agrammatic production.

A time-based approach to agrammatic speech is presented. The paper consists of three parts. In the first part, the literature which deals with agrammatic comprehension as a problem of disrupted timing, that is, as a slow-down of syntactic computation and/or a rapid decay of the results of syntactic processing, is reviewed. In a second part, the hypothesis that similar timing problems cause difficulties in production as well is discussed. Two possible ways in which this can happen are described. First, slow down or rapid decay can lead to desynchronization within the process of syntactic tree formation. Second, a slow down of syntactic processing can cause asynchrony between the production of a syntactic slot and the retrieval of the proper grammatical morpheme from the mental lexicon. This hypothesis predicts that morphemes which are dependent on a relatively complex part of the syntactic tree will elicit relatively many errors. Results from the literature which seem to confirm this prediction are discussed. In the third part of the paper, the possible ways in which a patient can adapt to the reduced temporal window that would result from a timing deficit are discussed. Message simplification will reduce the size of the required temporal window and will therefore have a beneficial effect on the error rate. Restart of the computational process will profit from previously reached activation levels so that synchrony is easier to reach and error rate is reduced. Empirical work which appears to support these hypotheses is reviewed.

Aphasia↗

PubMed1993

The covert repair hypothesis: prearticulatory repair processes in normal and stuttered disfluencies.

Self-repairing of speech errors demonstrates that speakers possess a monitoring device with which they verify the correctness of the speech flow. There is substantial evidence that this speech monitor not only comprises an auditory component (i.e., hearing one's own speech), but also an internal part: inspection of the speech program prior to its motoric execution. Errors thus may be detected before they are actually articulated. In the covert repair hypothesis of disfluency, this internal error detection possibility has been extended with an internal correction counterpart. Basically, the covert repair hypothesis contends that disfluencies reflect the interfering side-effects of covert, prearticulatory repairing of speech programming errors on the ongoing speech. Internally detecting and correcting an error obstructs the concurrent articulation in such manner that a disfluent speech event will result. Further, it is shown how, by combining a small number of typical overt self-repair features such as interrupting after error detection, retracing in an utterance, and marking the correction with editing terms, one can parsimoniously account for the specific forms disfluencies are known to take. This reasoning is argued to apply to both normal and stuttered disfluency. With respect to the crucial question concerning what makes stuttering speakers so greatly disfluent, it is hypothesized that their abilities to generate error-free speech programs are disordered. Hence, abundant stuttering derives from the need to repeatedly repair one's speech programs before their speech motor execution.

Auditory Perception↗

PubMed1992

The effects of noise masking and required accuracy on speech errors, disfluencies, and self-repairs.

The covert repair hypothesis views disfluencies as by-products of covert self-repairs applied to internal speech errors. To test this hypothesis we examined effects of noise masking and accuracy emphasis on speech error, disfluency, and self-repair rates. Noise reduced the numbers of disfluencies and self-repairs but did not affect speech error rates significantly. With accuracy emphasis, speech error rates decreased considerably, but disfluency and self-repair rates did not. With respect to these findings, it is argued that subjects monitor errors with less scrutiny under noise and when accuracy of speaking is unimportant. Consequently, covert and overt repair tendencies drop, a fact that is reflected by changes in disfluency and self-repair rates relative to speech error rates. Self-repair occurrence may be additionally reduced under noise because the information available for error detection--that is, the auditory signal--has also decreased. A qualitative analysis of self-repair patterns revealed that phonemic errors were usually repaired immediately after their intrusion.

Adult↗

PubMed1992

Error monitoring in people who stutter: evidence against auditory feedback defect theories.

Several theories purport that people who stutter suffer a speech-auditory feedback defect. The disordered feedback creates the illusion that some kind of error has intruded into the speech flow. Stuttering then results from actions aimed to correct the suspected, but nonexistent, error. These auditory feedback defect theories thus predict deviant error detection performance in people who stutter during speech production. To test this prediction, subjects who stuttered and those who did not had to detect self-produced (phonemic) speech errors while speaking with normal auditory feedback and with the auditory feedback masked by white noise. The two groups did not differ significantly in error detection accuracy and speed, nor in false alarm scores. This opposes auditory feedback defect theories and suggests that the self-monitoring processes of people who stutter function normally. In a condition in which errors had to be detected in other-produced speech, i.e., while listening to a tape recording, subjects who stuttered did detect fewer errors. Whether this might signal some general phonological problem is discussed.

Adult↗

PubMed1991

Manual reaction times and error rates in stutterers.

In this study 18 stutterers and 18 nonstutterers were presented trials on which they should press a button as fast as possible, intermixed with trials which required no responding. Stutterers had slightly faster reaction times but also made slightly more errors, that is, they tended to press the button when they should not have done so. As neither difference was significant, it was concluded that stutterers did not differ from normal speakers in manual reaction speed, nor did they choose a different speed-accuracy trade-off criterion for the given task.

Adult↗

PubMedDate not supplied

On the relation among speech errors, disfluencies, and self-repairs.

In this study the relationship between speech errors (deviations from a speech plan), disfluencies (interruptions in the execution of a speech plan), and self-repairs (corrections of speech errors) was examined. Two hypotheses were formulated: Either disfluencies are special types of speech errors, or they resemble self-repairs (i.e., they are corrective actions applied to anticipated, internal errors). To test these two hypotheses, patterns of speech errors, disfluencies, and self-repairs were compared in a task in which speakers recited stimulus sentences four times in succession under time pressure. Subjects in one condition were explicitly instructed to pay close attention to accuracy of speaking. In another condition subjects were told that speech accuracy was not important. A much lower speech error rate was found in the higher-accuracy condition, but rates of disfluencies and self-repairs did not differ significantly between the two accuracy conditions. This is regarded as support for the self-repair account of disfluencies. When accuracy of speaking is stressed, speakers tend to avoid and repair speech errors at the cost of reduced speech fluency.

Adolescent↗