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Biomedical subjects

H Harder

Publications and source records attributed to H Harder.

At least 37 records · Page 2Linked to original sources
PubMed1999

Rapid reversal of nephrotic syndrome due to primary systemic AL amyloidosis after VAD and subsequent high-dose chemotherapy with autologous stem cell support.

In a patient with nephrotic syndrome, renal biopsy revealed AL amyloid deposits. Monoclonal lambda light chains were identified in serum and urine. A low percentage of monoclonal plasma cells was detected in the bone marrow. The patient received four cycles of VAD and subsequent high-dose chemotherapy (HDCT) with melphalan (200 mg/m2) followed by autologous peripheral blood stem cell transplantation. Proteinuria rapidly diminished during chemotherapy. Three months after HDCT, the patient has no edema, and no signs of plasma cell dyscrasia are currently detectable. Using VAD before starting HDCT may improve the condition of patients with amyloidosis and reduce transplantation-related morbidity and mortality.

Amyloidosis↗
PubMed1999

Effect of 7-day therapy with different doses of the proton pump inhibitor lansoprazole on the intragastric pH in healthy human subjects.

BACKGROUND: Systematic, randomized, and controlled studies on the effect of low to high doses of the proton pump inhibitor lansoprazole on intragastric acidity and plasma gastrin levels have not previously been performed. METHODS: We investigated the effect of 7-day therapy with different doses of lansoprazole (15 mg once or twice daily, 30 mg once or twice daily, and 15 mg three times daily) on intragastric acidity and meal-stimulated daytime plasma gastrin levels in 12 healthy Helicobacter pylori-negative human subjects in a randomized, double-blind, placebo-controlled, 6-way crossover study. On days 1, 2, and 7 of the study 24-h intragastric pH-metry and 12-h integrated daytime plasma gastrin determinations were done. RESULTS: Lansoprazole in a dose regimen of 1 x 30 mg/day, 3 x 15 mg/daily, and 2 x 30 mg/day significantly (P < 0.05) increased the intragastric 24-h median pH on days 1, 2, and 7 of therapy as compared with placebo. Lansoprazole in doses of 1 x 15 mg/day and 2 x 15 mg/day significantly increased the intragastric 24-h median pH on days 2 and 7 but not on day 1 of therapy. Doses of 3 x 15 mg and 2 x 30 mg lansoprazole daily significantly increased the intragastric 24-h median pH on days 2 and 7 of treatment as compared with 1 x 30 mg lansoprazole daily. Except for 1 x 15 mg lansoprazole on day 1 of therapy, all given dose regimens of lansoprazole (15-60 mg/day) significantly (P < 0.05) stimulated the 12-h integrated meal-stimulated daytime plasma gastrin response (pM x min) on days 1, 2, and 7 of therapy as compared with placebo. CONCLUSION: A dose of 1 x 30 mg/day is nearly as potent as higher dose regimens of lansoprazole. Thus it most likely is the optimum dose for therapy of gastric and duodenal peptic lesions. A dose of 1 x 15 mg lansoprazole daily is a potent inhibitor of gastric acid output and could be a therapeutic dose for prevention of peptic lesions (that is, reflux oesophagitis or ulcers).

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Indeterminacies in the vt(E) = 1 Levels of C3v Symmetric-Top Molecules

The theory of the reduction of the effective rotation-vibration Hamiltonian for vt(E) = 1 states of C3v molecules of E. I. Lobodenko et al. (1987, J. Mol. Spectrosc. 126, 159-170) has been extended to include higher-order terms. Constraints suitable for most cases are proposed and alternative choices are discussed. Relations previously observed empirically among the higher-order parameters are explained by the extended reduction theory, and new relations are derived. Good agreement between the theoretical predictions and the experimental data is observed. Copyright 1998 Academic Press. Copyright 1998Academic Press

Journal Article↗
PubMed1998

Phonological representation and speech understanding with cochlear implants in deafened adults.

In the present study cognitive performance in 15 deafened adult cochlear implant candidates was examined and related to level of speech understanding after 12 months of experience with the implant. The implant group performed on par with normal hearing controls in all cognitive tasks used in the study with one exception: Performance was significantly lower in cognitive tasks where use of a phonological representation of sound is a key task-demand. Observations of the implanted individuals' level of speech understanding indicate that only those individuals who, pre-operatively, were in possession of phonological representations comparable to that of normal hearing could follow and understand a speaker that was out of sight. The results are discussed with respect to (a) deterioration in the phonological representation of sounds as a function of absence of external auditory stimulation, and (b) the role of cognitive factors in predicting success in speech understanding with the implant.

Adult↗
PubMed1998

A review: acute and chronic effects of ethanol and alcoholic beverages on the pancreatic exocrine secretion in vivo and in vitro.

Whereas oral or intraduodenal ethanol causes a moderate stimulation of pancreatic bicarbonate and enzyme output, intravenous ethanol inhibits basal and hormonally stimulated pancreatic exocrine secretion in humans, dogs, cats, pigs, rabbits, and rats. This inhibition could be mediated by inhibitory cholinergic mechanisms or be the result of a direct cellular effect of ethanol. In vitro investigations have specified several signaling molecules that may be involved in the action of ethanol on stimulus-secretion coupling in the exocrine pancreas, including cyclic adenosine monophosphate, intracellular calcium, and cholecystokinin and somatostatin receptors. In difference to pure ethanol solutions and distilled spirits, beer strongly stimulates pancreatic enzyme output, probably by nonalcoholic fermentation products. During chronic alcoholism, the ethanol-induced inhibition is replaced by an enhanced enzyme output that causes intraductal protein precipitation. In vitro investigations suggest that this increase is reversible after alcohol withdrawal. The occurrence of protein precipitates is considered to be a crucial step in the development of chronic alcoholic pancreatitis in humans. Other ethanol-induced secretory alterations that may contribute to the development of alcoholic pancreatitis are a decreased secretion of trypsin inhibitor, an increased cholinergic tone, and changes in the concentration of lithostathine.

Alcoholic Beverages↗
PubMed1998

Three-Dimensional Fast Spin-Echo T2-Weighted Magnetic Resonance Images of the Cerebellopontine Angle.

In patients experiencing dizziness and hearing disorders, it is essential to rule out the possibility of an intracranial affection, typically a cerebellopontine angle (CPA) process. Clinically, this often is accomplished using audiology and otoneurology and by interpreting the time course of the symptoms. However, in many cases, we must resort to imaging of the skull base and the CPA. The use of thin-section, fast spin-echo, heavily T2-weighted images can eliminate the need for gadolinium contrast administration, offering a cheaper and quicker investigation as compared with the customary T1-weighted images using gadolinium. With three-dimensional volume sampling, slice thickness can be reduced to 0.7 mm. Data reconstruction in every desired direction is possible. Ninety-two patients with hearing and balance disorders were examined using this method. In subjects free of tumor in the CPA, the seventh and eighth nerves could be followed accurately from the internal auditory meatus to the brainstem. The tumors could be outlined with reasonable accuracy even without gadolinium contrast. Three-dimensional, fast spin-echo, T2-weighted images are useful in evaluating the CPA in cases of suspected tumor. Most often the use of gadolinium can be avoided. This seems to be a cheap alternative for magnetic resonance screening of patients experiencing dizziness and hearing disorders.

Journal Article↗
PubMed1997

Hearing results in otosclerosis surgery after partial stapedectomy, total stapedectomy and stapedotomy.

Hearing results in a consecutive series of 407 patients with otosclerosis undergoing primary stapes surgery were analysed (437 operated ears). Partial stapedectomy was performed in 70 ears (16%), total stapedectomy in 205 ears (47%), in both groups using the House steel wire prosthesis on fascia in the oval window. The remaining 162 ears (37%) underwent stapedotomy using the Fisch 0.4 mm teflon-platinum piston. No case of cochlear loss (> 15 dB) occurred in the total series. The comparison between the three groups one year postoperatively showed that the air-bone gap was smaller for partial and total stapedectomy for all frequencies except 4 kHz. The air-bone gap was calculated as the difference between the preoperative bone conduction and the postoperative air conduction thresholds. Partial and total stapedectomy also showed larger improvements of bone conduction thresholds compared with stapedotomy for all frequencies but 4 kHz. At the 3-year follow-up, the hearing gain for all frequencies (250-8000 Hz) was larger for partial and total stapedectomy. Yet, when comparing the decline of hearing from 1 to 3 year postoperatively, the hearing gain achieved with partial and total stapedectomy seemed to deteriorate at a higher rate, which was considered to be caused by impaired sensorineural function. Our results show that in the short-term perspective partial or total stapedectomy can still compete for better hearing results even at higher frequencies, but stapedotomy seems to yield more stable hearing results over time and should therefore be considered as the method of choice.

Adolescent↗
PubMed1996

Effect of beer, yeast-fermented glucose, and ethanol on pancreatic enzyme secretion in healthy human subjects.

The effect of beer, ethanol (4% v/v), and corresponding volumetric (water), caloric (glucose 5.76% w/v), and osmotic (glucose 11.5% w/v) control solutions on pancreatic enzyme output and release of gastrin and cholecystokinin (CCK) were studied in six healthy human subjects. As a simpler model of beer, yeast-fermented glucose solution (11.5% w/v) was also studied and compared with unfermented glucose (11.5% w/v). Among the control solutions, the two glucose solutions, but not water, significantly (P < 0.05) increased the 150-min integrated trypsin and amylase output over basal levels. Beer and fermented glucose caused a significantly higher increase in trypsin and amylase output compared to water or glucose. Ethanol (4% v/v) failed to stimulate pancreatic enzyme output. Fermented glucose and beer, but not the control solutions, significantly increased plasma gastrin levels above basal values. Isotonic and hypertonic glucose, beer, and fermented glucose significantly increased plasma levels of cholecystokinin (CCK), but the effect was significantly higher after hypertonic glucose than after isotonic glucose, beer, or fermented glucose. Ethanol and water had no effect on plasma levels of gastrin and CCK. We conclude that: (1) in the doses studied intragastric beer and fermented glucose but not ethanol (4% v/v) stimulate pancreatic enzyme output and release of gastrin and CCK; (2) the lack of effect of ethanol indicates that nonalcoholic ingredients of beer and fermented glucose are responsible for this stimulatory effect; and (3) CCK could be one of the major mediators of the stimulation of pancreatic enzyme output after ingestion of beer and fermented glucose.

Adult↗
PubMed1996

Verbal information-processing capabilities and cochlear implants: implications for preoperative predictors of speech understanding.

In this study, we examined preoperative verbal cognitive capacity in 11 deafened adults who were cochlear implant candidates and reexamined level of speech understanding after 6-8 months' experience with the implant. Verbal cognitive performance in the implant group was compared in a group of normal hearing subjects and in nonimplanted group of deafened adults. The three groups performed on par with each other with an exception: The individuals in the cochlear implant group and the nonimplanted group of deafened adults performed significatly worse than those of normal hearing in tasks in which use of internal speech is a key feature (i.e., rhyme judgement and lexical decision tasks). Postoperative observations of the implanted individuals' level of speech understanding suggest that it is possible to predict the level of speech understanding by means of a properative cognitive assessment. The characteristics of three verbal cognitive abilities prove to be critical indicators of 6 - 8 months' postoperative outcome: internal speech functioning, speed of verval information processing, and working memory capacity - the first factor proved the most decisive. We discuss the results with respect to direct versus indirect predictors of outcomes from cochlear implant operations and the effect of auditory deprivation on deafened adults' capability to process auditory information.

Journal Article↗
PubMed1995

[The Mini Mental Status test inadequate as screening test for cognitive deterioration in a neurological department].

OBJECTIVE: To study the validity of the Mini-mental state (MMS) in a neurological population. DESIGN: Comparing the results of a neuropsychological examination and the MMS score. SETTING: Departments of Neurology/Neuropsychology of the University Hospital Leiden. METHODS: One hundred and forty-seven patients participated in the study. One hundred and eight patients were classified into two diagnostic groups according to the deterioration index (obtained from test results of the neuropsychological examination) and DSM-III-R criteria: 63 patients had dementia, 45 did not; the other 39 patients were found to have specific cognitive impairments and were excluded from the group comparisons. The discriminative powers of the deterioration index and the MMS were compared; sensitivity and specificity were determined with several cut-off scores of the MMS. RESULTS: The MMS had limited power to discriminate between demented and non-demented patients. The MMS score was strongly related to premorbid intelligence, occupational level and age. Increasing the original cut-off score to 25 points improved sensitivity and specificity to 79% and 84% respectively (with the original cut-off level these were 68% and 93%). CONCLUSION: The diagnostic value of the MMS is limited, especially in patients for whom a correct diagnosis is most relevant.

Aged↗
PubMed1988

Audiovestibular tests in the diagnosis of cerebellopontine angle tumours.

Symptoms and signs were recorded in a series of 78 patients with a cerebello-pontine-angle (CPA) tumour and in 92 patients with symptoms and signs suggestive of such a lesion but with a negative CT scan. Variable symptomatology was found in the tumour cases. A substantial proportion of the patients had experienced sudden phenomena such as rotatory vertigo and/or sudden hearing loss. A CPA tumour must therefore be considered in almost every case of unilateral auditory or vestibular disturbances. Unfortunately, conventional audiovestibular tests have a low sensitivity of around 50%, with the exception of stapedial reflex threshold elevation (89%). The specificity on the other hand is quite low for this test, whereas other test results, like a genuinely pathological stapedial reflex decay, carry a high specificity of 60%. However, brainstem response audiometry (BRA) exhibited a very high sensitivity (100%) coupled with a reasonable specificity (54%), making it a suitable single test for screening patients suspected of having a CPA tumour. A program for the diagnostic work-up is suggested.

Adult↗