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Biomedical subjects

J Jakobsen

Publications and source records attributed to J Jakobsen.

At least 19 recordsLinked to original sources
PubMed1992

The influence of haematocrit and blood glucose on cerebral blood flow in normal and in diabetic rats.

Cerebral blood flow (CBF) was measured at varying haematocrit values in 8 streptozotocin-diabetic and in 7 control rats using the intracarotid 133Xe technique. A hyperbolic relationship between CBF and haematocrit was established for the individual rats in both groups. Diabetic animals showed a preserved CBF response to changes to haematocrit. In 10 normal rats, CBF was measured during acute hyperglycaemia induced by intraperitoneal glucose injection. A significant, inverse correlation was found between CBF and blood glucose. We conclude that the CBF response to changes in haematocrit and thereby in pO2 is preserved in experimental diabetes. Secondly, in acute hyperglycaemia CBF varies inversely with blood glucose, by mechanisms not fully understood.

Animals↗
PubMed1992

A comparison of three methods for estimating dental plaque removal from individual teeth.

The purpose of this study was to determine the efficiency of dental plaque removal, in vitro, by physical force. Of the 3 methods used, turbidity was the most sensitive for measuring microgram amounts of plaque. Air-dried weight and dental plaque imprint assays (DPIA) complemented turbidity measurements by providing a weight standard and a new method for visualizing plaque bacterial structure before the stained imprint was transformed into numerical data. The amount of dental plaque removed from a tooth by physical force can be measured and described as a percentage of the total removable plaque on that tooth.

Analysis of Variance↗
PubMed1992

The influence of halothane on spermatogenesis in surgical patients.

Seventeen male patients delivered a sperm sample before and 80-90 days after halothane anaesthesia, acting as their own control. The sample was tested according to WHO criteria. There was no difference before and after anaesthesia. We conclude that halothane used in normal anaesthetic concentration in combination with nitrous oxide during arthroscopic knee surgery had no certain effect on the quality of sperm.

Adult↗
PubMed1992

Lymph node metastases in the neck from unknown primary tumour.

During a 12-year period a total of 203 patients were referred to the oncologic center of Odense with lymph node metastases in the neck. Routine examinations on admission failed to detect the primary tumour in 37 patients. During follow-up, the primary was revealed in 18 of these patients, and in a further 8 cases it was found at autopsy. The primary was most often located in the head and neck region with a possibility of curative therapy. Patients with small neck node metastases responded well to treatment with neck dissection and radiotherapy, resulting in a 5-year crude survival rate of 53%.

Adenocarcinoma↗
PubMed1992

Unmasking of the hypotensive effect of nifedipine in normotensives by addition of the angiotensin converting enzyme inhibitor benazepril.

OBJECTIVE: To study the pharmacological interaction between a dihydropyridine derivative (nifedipine slow release 20 mg) and inhibition of the renin-angiotensin system (benazepril 10 mg). DESIGN: Single application at intervals of 2 weeks in an open-label three-way cross-over design. SETTING: Institutional pharmacological unit. PARTICIPANTS: Nine healthy male volunteers. MAIN OUTCOME MEASURES(S): Blood pressure and heart rate were recorded in the supine position for 24 h as well as plasma drug levels, plasma angiotensin converting enzyme activity and active plasma renin concentration. RESULTS: Nifedipine increased active plasma renin two-fold and benazepril increased it five-fold. The combination of the two drugs accelerated the increase of active renin during the first 2 h after drug intake. Whereas no hypertensive effect could be detected after nifedipine or benazepril alone, a significant fall in systolic and diastolic blood pressure was observed for up to 9 to 12 h after the combination. The increase in heart rate induced by nifedipine was minimized by the addition of benazepril. There was no interaction between the pharmacokinetics of benazeprilate and nifedipine which would explain these pharmacodynamic effects. CONCLUSION: These results demonstrate that, in normotensive volunteers, the renin-angiotensin system contributes to mask the hypotensive effect of a single oral dose of dihydropiridine. The concomitant administration of a converting enzyme inhibitor discloses the hypotensive effect and limits the baroreflex-mediated increase in heart rate secondary to vasodilation.

Adult↗
PubMed1991

[Immunomodulator therapy of chronic inflammatory demyelinating polyradiculoneuropathy].

A group of 6 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) was treated with prednisone, azathioprine, plasma exchange and/or intravenous immunoglobulin. Three of the six patients improved during treatment with prednisone and two patients with severe CIDP both showed a remarkable therapeutic response to treatment with intravenous immunoglobulin.

Adjuvants, Immunologic↗
PubMed1991

[Functional endoscopic endonasal sinus surgery. First experiences with a new method].

A material of 46 patients who were treated operatively on account of chronic recurrent sinusitis by functional endoscopic sinus surgery by Messerklinger's method is presented. In 80% the operation was bilateral. As a serious complication, one case of dural lesion occurred. This healed without further complications and without sequelae. Just under 30% experienced slight per- or postoperative complications in the form of haemorrhage and infection. All of the patients participated in a follow-up examination after an average of 13 months' observation. 80-85% stated that they were free from symptoms or had improved after operation. Late complications were insignificant. Half of the patients had synechia formation in the resection area but the presence of synechia was not found to have any significant relationship to the postoperative course. When it is taken into consideration that the first experience with a new method is concerned, the results are considered to be satisfactory. A more extensive patient material with more prolonged observation and experience from other departments are necessary before the employability of the method in the Danish therapeutic system can be assessed.

Adolescent↗
PubMed1991

Tooth and bone development in a Danish medieval mandible with unilateral absence of the mandibular canal.

A Danish anthropological collection of medieval human skeletons excavated in 1986 involves a mandible (No. 212) from an adult female born without the lower alveolar nerve and mandibular canal. It is believed that the defect has resulted in lack of tooth development on the affected side and that the mylohyoid nerve has partially compensated for this defect by development of teeth in localized areas. The defective mandibular dentition has caused a compensatory development of the alveolar process in the maxilla. The missing occlusal support has altered muscular traction on the mandible. This has caused an alteration in mandibular shape. Whether the asymmetric development of the mandible is caused by muscular dysfunction, by failure in angular growth apposition, or by a combination of these factors is discussed. The case presents valuable data in the ongoing discussion about the interaction between nerve tissue and tooth formation and about the interaction between occlusion, jaw morphology, and muscular traction. The study shows how archeological material in an interdisciplinary cooperation between archeological, embryological and orthodontic research can contribute to the clarification of current biological problems.

Alveolar Process↗
PubMed1991

Differences in need for orthodontic treatment between Native Americans and the general population based on DAI scores.

Clinical impressions by Indian Health Service (IHS) dentists of a greater frequency of severe dental malrelations among Native Americans than in the general US population have never been objectively confirmed. This study uses the DAI as the standard to determine whether there is a greater prevalence of severe malocclusions among Native Americans. Four hundred eighty-five Native American students in grades 7-12 from two remote sites--Pine Ridge, SD, and Many Farms, AZ--and one nonremote site--Lapwai, ID--were scored for the DAI. The mean scores from each reservation, as well as the mean score from the three reservations combined, were significantly higher, indicating poorer aesthetics, than the mean DAI score from a large sample of the general US population. These data confirm the clinical impressions of IHS dentists that Native Americans residing on reservations have significantly poorer dental aesthetics than the aesthetics found in the general US population; therefore, Native Americans have greater needs for orthodontic treatment.

Adolescent↗
PubMed1991

[Identification of victims after a fire on the ferry "Scandinavian Star"].

Cooperation between Scandinavian Victim Identification Commissions was tested thoroughly after the ship disaster at Easter 1990. The fire claimed 158 victims all killed by poisonous smoke from a fast spreading fire, which went on for 36 hours. Many of the bodies were found incinerated in burnt-out cabins. More than 100 specialists were at work for 17 days before all missing persons were identified. The whole operation was led by the Norwegian authorities in Oslo. They decided that a search for human remains should be attempted in the destroyed part of the ship by help of police technicians, forensic pathologists and forensic dentists. The placing of forensic and dental expertise at the site of the disaster made it possible to identify all victims of the fire. Eighteen forensic trained dentists supported the work: thirteen from Norway, four from Denmark and one from Iceland. Two of the Danish dentists were placed at police headquarters in Copenhagen preparing the antemortem data from the Danish passengers on the ship.

Denmark↗
PubMed1990

Adaptability of two amalgams to finished cavity walls in Class II cavity preparations.

Adaptability of two amalgams--the dispersed-phase Dispersalloy and the spherical-particle-type Sybralloy--to cavity walls in a Class II cavity preparation was investigated. Four techniques for finishing cavity walls were compared, as was the adaptability of alloys at different occluso-gingival levels. The issues were examined by direct measurement of microleakage between cavity wall and the amalgam without the use of cavity varnish. There was no statistically significant difference in the adaptability of the two amalgams directly to the cavity walls, except those finished by a sharp hand instrument (hatchet) and restored with Dispersalloy. This combination demonstrated the best overall adaptability of amalgam to cavity walls. Sybralloy demonstrated best adaptability to walls finished with sandpaper discs. Although not significant, the gingival 1/3 of the Class II cavity preparation had more microleakage than the middle 1/3 or the occlusal 1/3, suggesting greater potential for recurrent decay. Overall dispersalloy demonstrated significantly better adaptability than Sybralloy.

Dental Alloys↗
PubMed1990

Myelopathy and HIV infection.

The clinical significance of myelopathy associated with HIV infection is poorly understood. Recently, a prospective electrophysiological follow-up study of spinal-evoked potentials in HIV-seropositive men without AIDS revealed a 32% prolongation of the latency from the gluteal crease to the 12th thoracic vertebra (T12) following tibial nerve stimulation at the ankle performed after an interval of 2 years. In AIDS patients this transmission delay did not increase further. Instead, the latency prolongation took place proximal to T12. We assume that myelopathy is an integral part of HIV infection that it is asymptomatic in the early disease phase, spreads from the lumbar part the spinal cord in a rostral direction and leads to the development of leg weakness and ataxia during the later stages of the disease.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The acute effect of dilevalol on cerebral blood flow and oxygen consumption in normotensive humans.

The antihypertensive agent dilevalol, a stereoisomer of labetalol, causes vasodilatation by combined beta-adrenergic blockade and direct beta 2-receptor agonism. The acute effect of a single oral dose of 400 mg dilevalol on cerebral blood flow (CBF), and its response to induced changes in arterial carbon dioxide tension (PaCO2), and the cerebral metabolic rate of oxygen (CMRO2) were studied after 1, 2, and 4 h in eight normotensive volunteers. Serum dilevalol 2 h after oral intake ranged between 22 and 49 ng/ml. Mean arterial blood pressure was reduced from 93 +/- 8 to 86 +/- 8 mm Hg (p less than 0.01). An analysis of variance of the successive differences of CBF during the study showed that dilevalol altered CBF significantly. After 1 h CBF had decreased by 4.4% (p less than 0.05), whereas the 2 and 4 h values were similar to the pretreatment level. CMRO2 showed a tendency for reduction (p = 0.086). The CBF response to changes in PaCO2 remained unchanged. It is concluded that a single dose of dilevalol induces a slight and short-lasting decrease in CBF, probably due to a direct effect on brain metabolism.

Administration, Oral↗
PubMed1990

Improved energy kinetics following high protein diet in McArdle's syndrome. A 31P magnetic resonance spectroscopy study.

A patient with McArdle's syndrome was examined using bicycle ergometry and 31P NMR spectroscopy during exercise. The patients working capacity was approximately half the expected capacity of controls. Muscle energy kinetics improved significantly during intravenous glucose infusion and after 6 weeks of high protein diet. During intravenous infusion of amino acids, no changes in working capacity could be detected. No decrease was seen in intracellular muscle pH during aerobic exercise. A significant decrease in muscle pH during aerobic exercise was detected in all controls.

Adult↗
PubMed1990

Pupillary function in multiple sclerosis.

Eighteen MS patients with visual acuity of 20/30 or better and without recent visual complaints, and 14 age- and sex-matched controls were studied by TV pupillography. The response amplitude and the maximum rate of pupillary constriction or dilation of the light, dark, accommodation and ciliospinal reflexes were unchanged. The latency of the pupillary light response (PLR), however, was prolonged and closely related to walking performance (R = 0.76; p less than 0.001). No relationship was established between PLR latency and previous history of optic neuritis or latency of the VEP. It is concluded that MS patients with preserved visual acuity have only discrete autonomic pupillary disturbances and that the PLR delay is related to disease progression.

Adult↗
PubMed1990

Caries: a problem in an overdenture population.

A series of 254 patients who had their overdentures constructed at a University clinic from 1973 to 1985 were followed longitudinally. This paper reports on the caries experience in the abutment teeth of these patients. The mean age of the patients at the time of insertion of the dentures was 58.6 yr. The overall rate for new caries was 6.5% of the abutment teeth per year. The highest rate for the maxilla was 15.4%, which occurred during the 5th yr, and in the mandible it was 11.0%, which occurred in the 4th yr. A regression model was developed to profile individuals susceptible to caries. The Logistic Regression model identified a list of predictor variables which included frequency of brushing, use of home fluoride, and disease and drug effect. However, discriminant function analysis showed that although specificity was very high (98.5%), sensitivity was very low (7.9%). Therefore, this model was unable to predict persons who would be at high risk for caries.

Adult↗