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Biomedical subjects

H Haak

Publications and source records attributed to H Haak.

At least 19 recordsLinked to original sources
PubMed2002

Sacral insufficiency fracture, an unsuspected cause of low-back pain in elderly women.

Sacral insufficiency fractures (SIF) usually occur in elderly women and are secondary to various conditions, mainly postmenopausal or steroid-induced osteoporosis and radiation therapy. They are often overlooked or confused clinically and radiographically with metastatic disease. We report a case of a 72-year-old woman who presented to our department with severe low-back pain. She was thoroughly investigated for the cause of her back pain. Plain X-rays did not reveal any abnormality, but magnetic resonance (MR) scan revealed marked oedema within both sides of the sacrum, suggesting a neoplastic lesion. Bone scintigraphy did show a hyperfixation pattern forming an 'H' in the sacrum which is a characteristic sign of SIF. Computed tomography (CT) confirmed sclerotic changes interpreted as insufficiency fractures through both sacral alae. Increased awareness of these fractures may help to avoid unnecessary investigations and treatment. Bed rest and analgesia followed by rehabilitation provide good relief of symptoms.

Aged↗
PubMed2002

The effect of limited interlaminar decompression versus complete laminectomy on intrathecal volume in degenerative lumbar spinal stenosis.

INTRODUCTION: There is a controversial discussion about the adequate surgical procedure for degenerative lumbar spinal stenosis. Due to the observation that the degenerative lumbar spinal stenosis takes place predominantly at the interlaminar region on the level of the disc involving facets and bulging of the ligamentum flavum, resection of the whole lamina might not be necessary. A biomechanical study was designed to assess the effect of different decompression techniques using cadaver lumbar spine models. METHODS: Twelve cadaver spines with CT verified degenerative lumbar spinal stenosis were dissected in order to measure the volume of the dural sac at different flexion and extension angles. Each segment (L3/4, L4/5) was decompressed first by limited interlaminar decompression and second by complete laminectomy. Intrathecal volume measurements were taken initially, after limited interlaminar decompression and after complete laminectomy. RESULTS: Before surgical procedure, the cadaver spines showed an increase of the intrathecal volume in flexion and decrease in extension. After limited interlaminar decompression, there was a significant reduction of volume loss in extension. There was no significant additional reduction of volume loss in extension after complete laminectomy in comparison to limited interlaminar decompression. CONCLUSION: The results allow to conclude that limited interlaminar decompression is efficient for decompression in degenerative lumbar spinal stenosis.

Aged↗
PubMed2001

Is sacral instrumentation mandatory to address pelvic obliquity in neuromuscular thoracolumbar scoliosis due to myelomeningocele?

STUDY DESIGN: Prospective study. OBJECTIVE: To evaluate the functional outcome of two-stage anterior and posterior instrumented fusion without fixation to the sacrum on 11 patients with neuromuscular scoliosis from thoracolumbar myelomeningocele. SUMMARY OF BACKGROUND DATA: To our knowledge, there are no published results of combined anterior and posterior correction and fusion without inclusion of the sacrum in neuromuscular scoliosis from thoracolumbar myelomeningocele. In this article we present our experience and critically evaluate the functional outcome on 11 patients with neuromuscular scoliosis. PATIENTS AND METHODS: From July 1, 1992 through June 30, 1995, 11 consecutive patients with severe thoracolumbar scoliosis were admitted at our hospital. The mean age at operation was 12 years 9 months (range 9 years 9 months to 14 years 6 months). All patients underwent a two-stage anterior and posterior spinal reconstruction. The patients were evaluated before surgery and after surgery. RESULTS: All patients were observed for a mean of 4 years 11 months (range 42-88 months) from the time of second stage procedure. Before treatment the mean scoliosis was 81 degrees (range 55-110 degrees ); this was reduced to a mean of 31 degrees (range 8-70 degrees ), and at the final follow-up the correction had deteriorated slightly to a mean of 35 degrees (range 12-80 degrees ). No patient had increased neurologic deficit or showed other major complication. CONCLUSIONS: Pelvic obliquity in thoracolumbar neuromuscular scoliosis from lumbosacral myelomeningocele spontaneously corrected when the scoliotic deformity is adequately addressed with instrumented fusion without inclusion of the sacrum. The correction obtained remained stable at follow-up. In the absence of a control group we believe that sparing lumbar segments from primary fusion offers these patients a better freedom of mobility.

Adolescent↗
PubMed1999

Increasing genome instability in adrenocortical carcinoma progression with involvement of chromosomes 3, 9 and X at the adenoma stage.

The investigation of chromosomal aberrations in adrenocortical tumours has been limited by the difficulties of applying classical cytogenetics to tumours with low levels of proliferation. We have therefore applied the technique of interphase cytogenetics to paraffin-embedded archival specimens of 14 adrenocortical adenomas and 13 carcinomas. Hybridizations were performed using centromere-specific probes to chromosomes 3, 4, 9, 17, 18 and X, which have been shown to be altered in other types of tumours. Chromosomal imbalance was defined on the basis of changes in both chromosome index (CI) and signal distribution (SD). Where only one of these was altered, this was classified as a tendency to gain or loss. On the basis of the analysis of optimal hybridizations, carcinomas showed gains in all chromosomes studied, five of nine showing gains in multiple chromosomes. Gains were most common in chromosomes 3, 9 and, in particular X, eight of 11 showing gain, and one a tendency to gain. Chromosomal gain was seen less commonly in adenomas, but again chromosomes 3, 9 and X were involved. Losses were infrequent, only one carcinoma showing loss of chromosome 18, and adenomas showing a tendency to loss of chromosomes 4 (two cases), 17 (one case) and 18 (two cases). Our data suggest that changes in chromosomes 3, 9 and X are early events in adrenocortical tumorigenesis, and that there is increasing chromosomal instability with tumour progression.

Adenoma↗
PubMed1998

Mitoxantrone versus daunorubicin in induction-consolidation chemotherapy--the value of low-dose cytarabine for maintenance of remission, and an assessment of prognostic factors in acute myeloid leukemia in the elderly: final report. European Organization for the Research and Treatment of Cancer and the Dutch-Belgian Hemato-Oncology Cooperative Hovon Group.

PURPOSE AND METHODS: Optimization of remission-induction and postremission therapy in elderly individuals with acute myeloid leukemia (AML) was the subject of a randomized study in patients older than 60 years. Remission-induction chemotherapy was compared between daunomycin (DNR) 30 mg/m2 on days 1, 2, and 3 versus mitoxantrone (MTZ) 8 mg/m2 on days 1, 2, and 3, both plus cytarabine (Ara-C) 100 mg/m2 on days 1 to 7. Following complete remission (CR), patients received one additional cycle of DNR or MTZ chemotherapy and were then eligible for a second randomization between eight cycles of low-dose (LD)-Ara-C 10 mg/m2 subcutaneously every 12 hours for 1 2 days every 6 weeks or no further treatment. RESULTS: A total of 242 patients was randomized to DNR and 247 to MTZ. Median age of both study groups was 68 years. Secondary AML was documented in 26% and 25% of patients in either arm. The probability of attaining CR was greater (P = .069) with MTZ (47%) than with DNR (38%). Median duration of neutropenia was 19 (DNR) and 22 days (MTZ). The greater response rate to MTZ therapy correlated with reduced occurrence of chemotherapy resistance (32% v 47%, P = .001). With a median follow-up of 6 years, 5-year disease-free survival (DFS) is 8% in each arm. Overall survival estimates are not different between the groups (6% v 9% at 5 yrs). Poor performance status at diagnosis, high WBC count, older age, secondary AML, and presence of cytogenetic abnormalities all had an adverse impact on survival. Secondary AML and abnormal cytogenetics predicted for shorter duration of CR. Among complete responders, 74 assessable patients were assigned to Ara-C and 73 to no further therapy. Actuarial DFS was significantly longer (P = .006) for Ara-C-treated (13% [SE = 4.0%] at 5 years) versus nontreated patients (7% [SE = 3%]), but overall survival was similar (P = .29): 18% (SE = 4.6%) versus 15% (SE = 4.3%). Meta-analysis on the value of Ara-C postremission therapy confirms these results. CONCLUSION: In previously untreated elderly patients with AML, MTZ induction therapy produces a slightly better CR rate than does a DNR-containing regimen, but it has no significant effect on remission duration and survival. Ara-C in maintenance may prolong DFS, but it did not improve survival.

Acute Disease↗
PubMed1996

Regulatory actions to enhance appropriate drug use: the case of antidiarrhoeal drugs.

Inappropriate drug use is a serious problem in the control of diarrhoeal diseases. To address this problem, the World Health Organization's Programme for the Control of Diarrhoeal Diseases reviewed the literature on the most commonly used antidiarrhoeal agents, and distributed the resulting document widely in 1990. Antidiarrhoeal drugs received simultaneous attention in the popular media as groups and individuals campaigned against their registration and use. This article evaluates the actions against antidiarrhoeal drugs taken by national drug regulators in the period during and after these events (January 1989 until December 1993). Information on regulatory actions was requested from countries and extracted from published and unpublished sources. Sixteen countries reported regulatory actions on 21 occasions during the period of study. The majority of actions concerned antimotility drugs; few were against adsorbents, antidiarrhoeal drugs containing antimicrobials, or adult formulae. Six countries took action against large and heterogenous groups of antidiarrhoeal drugs. Most actions occurred in the two-year period immediately following the distribution of the WHO review and the attention in the media. The sequence of distribution of the review, media coverage, and activities of dedicated groups and individuals, followed by a noticeable cluster of regulatory actions suggests a clear relationship. Further research is necessary to determine the relative role of each activity. There are several constraints to deregistration of profitable drugs and some drug regulators may have chosen to delay action until the end of the drug's registration cycle. Many more antidiarrhoeal drugs may lose their register in the future through a passive deregistration process. Deregistration of inappropriate drugs will probably take much time and widespread deregistrations are not likely. Furthermore, regulatory actions alone are probably insufficient to achieve a more appropriate use of drugs. More effect can be expected from simultaneous regulatory, managerial, and educational interventions directed at providers, combined with communication to the general public.

Adult↗
PubMed1995

Essential drugs for ration kits in developing countries.

Since the early 1980s drug ration kits have been used to improve the supply of essential drugs to rural health facilities in developing countries. This paper evaluates some of the experiences with kit systems in Angola, Bhutan, Democratic Yemen, Guinea-Conakry, Kenya, Mozambique, Sudan, Tanzania, Uganda and Zambia in relation to the selection of drugs for the kits and their quantities and cost. Data were collected through a review of published papers, annual reports and programme evaluations, by questionnaires among field staff and interviews with key experts. In comparing the 10 programmes, 21 drugs can be identified that are used in at least two-thirds of all kits. This list may be useful for evaluation and planning purposes. Six drugs (ORS, chloroquine and 4 antibiotics) usually account for over 60% of the cost of the kit. Careful monitoring of the price and quantities of these 6 drugs can therefore be very cost-effective. In the absence of reliable data on morbidity and drug needs in the initial phases of a kit system, the median drug quantities in kits from these 10 countries may serve as a starting point. Accumulating surpluses are sometimes perceived as a serious disadvantage of kit systems, ORS, benzylbenzoate solution and iron tablets are the three drugs that have most frequently accumulated. These drugs are relatively cheap and usually have a long shelf-life; in most programmes they have been successfully redistributed to other health facilities while the kit content was being adapted. The overall financial loss due to accumulation of surpluses is therefore limited. Most programmes have reached a stable kit content within two years.

Ambulatory Care Facilities↗
PubMed1994

A novel polyadenylation signal mutation in the alpha 2-globin gene causing alpha thalassaemia.

In a family of Indian origin we have identified a deletion of two bases at the polyadenylation signal sequence of the alpha 2-globin gene (AATAAA-->AATA). Three individuals heterozygous for this mutation display an alpha o-thalassaemia-like phenotype. Single-stranded conformation analysis and automatic sequencing showed no additional mutations in either alpha 1- or alpha 2-globin genes. A previously described polyadenylation sequence mutation (AATAAA-->AATAAG), alpha TSaudi alpha, causes HbH disease in homozygotes. In this study the patients heterozygous for the AATA(-AA) mutation show a similar phenotype observed in the alpha TSaudi alpha heterozygotes. This confirms the observation that the inefficient transcriptional termination due to mutations of the polyadenylation sequence of the alpha 2-gene might interfere with the alpha 1-gene expression.

Base Sequence↗
PubMed1989

[Drug consumption patterns in 2 villages of Bahia (Brazil)].

A study among families in two villages in rural Bahia, Brazil, reveals that presently pharmaceutical products, are being used in self-medication on a large scale. Traditional remedies appear to have a limited place only. People's attitude towards modern medicines proved to be highly positive. However, when biomedicaly evaluated, the use of the pharmaceutical products has to be considered irrational. Complicating factors are: 1) a preference for the application of pharmaceutical products in infants, 2) the high financial burden to which the population is subject resulting from drug acquisition and 3) the exaggerated expectation with regard to antibiotics, analgesics and vitamin preparations. It is recommended did to do more research into local conditions of drugs use, resulting in creative solutions for irrational drug-use. Self medication could become an important instrument in "Primary Health Care", provided that people have more information. Public Health could play a keyrole in this research and the consequent educational programmes.

Brazil↗
PubMed1988

Pharmaceuticals in two Brazilian villages: lay practices and perceptions.

Family use and understanding of modern medicines was studied in two villages in rural Bahia, Brazil. It emerged that pharmaceuticals figure in the treatment of most reported health problems. Nursing infants above all are treated with drugs frequently and intensively. The three most commonly used medicine-groups are antibiotics, analgesics and vitamins. The majority of these medications are 'prescribed' by a pharmacy attendant or the patient himself. Roughly half of the applied medications appear on neither the WHO list nor the Brazilian national list of 'essential drugs'. In almost one third of the cases studied 'dangerous' substances were used. If we consider the medications in use from a strictly biomedical viewpoint, it must be said that between half and two thirds of them ought to be regarded as irrational. A lot of money, moreover, is being spent on modern medicines. In one of the two villages, each week every family spent, on the average, a full day's wages to obtain a wide range of medications. The attitude of the families studied towards modern pharmaceuticals was highly positive. In general, people held the view that medicines should be used in the event of any sickness or discomfort. Possible hazards accruing from the use of modern medicines were scarcely acknowledged, if at all. Furthermore the notion obtained that many drugs should be used at the same time in cases of severe illness, or whenever a quick recovery was desired. A remarkably vigorous interest in diseases and their treatment was observed. Perhaps in this keen interest was a potential solution to problems of over-medication and the irrational use of pharmaceuticals in the Third World. The paper closes with a plea for providing more information about pharmaceuticals to consumers.

Attitude to Health↗