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Biomedical subjects

J Jacobsen

Publications and source records attributed to J Jacobsen.

At least 91 records · Page 5Linked to original sources
PubMed1989

Subarachnoid analgesia with hyperbaric 0.5% bupivacaine: effect of a 60-min period of sitting.

A prospective randomised study of the effect when the patient remained sitting for 2 (Group-2) or 60 min (Group-60) before being put in the supine horizontal position, was evaluated in 12 patients, aged 39-67 years and given a spinal anesthesia with 4 ml 0.5% bupivacaine in 8% glucose (hyperbaric). The maximal cephalad spread of analgesia was obtained after 12.5 min (median) in Group-2 and 75 min in Group-60 (P less than 0.01). The spread of sensory analgesia went to T-6 (Group-2) and L3 (Group-60) after 60 min (P less than 0.01). After 90 min the spread went to T6.5 in Group-60, the difference being statistically significant (P less than 0.001). Given as median and range the maximum cephalad spread in Group-2 was T6(T3-T10) and in Group-60 T6.5 (T2-T10).

Adult↗
PubMed1989

The Vogt-Koyanagi-Harada syndrome: association with hypothyroidism and diabetes mellitus.

A 45 year old Saudi male with poliosis, alopecia areata, vitiligo, anterior uveitis, inflammatory changes in the posterior pole of the retina and paraparesis presented with features of the Vogt-Koyanagi-Harada syndrome, uncontrolled diabetes mellitus and hypothyroidism. To the best of our knowledge the association of diabetes mellitus and hypothyroidism in this syndrome has not been reported previously.

Diabetes Mellitus, Type 1↗
PubMed1989

Infantile colic treated by chiropractors: a prospective study of 316 cases.

A prospective, uncontrolled study of 316 infants suffering from infantile colic and selected according to well-defined criteria shows a satisfactory result of spinal manipulative therapy in 94% of the cases. The median age of the infants was 5.7 wk at the beginning of the treatment. The results were evaluated by analysis of a diary continuously kept by the mother and an assessment file comprised by interview. The study was carried out as a multicenter study lasting 3 months and involving 73 chiropractors in 50 clinics. The results occurred within 2 wk and after an average of three treatments.

Child Behavior↗
PubMed1988

Role of chloride/bicarbonate antiport in the control of cytosolic pH. Cell-line differences in activity and regulation of antiport.

Sodium-linked and sodium-independent HCO3-/Cl- antiport was measured under different conditions in a number of cell lines. Transport of HCO3- was estimated from its effect on intracellular pH (pHi) measured with the fluorescent probe 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein. The associated ion fluxes were estimated from the transport of 36Cl- and 22Na+. Na+-dependent and Na+-independent HCO3-/Cl- antiport were found in many, but not in all cell lines tested. The Na+-independent HCO3-/Cl- antiport was found to be highly pHi-dependent in a number of cell lines, whereas in others this was not the case. Some cell lines were found to have both Na+-dependent and Na+-independent HCO3-/Cl- antiport, whereas in others we could detect only one of these mechanisms. Na+/H+ antiport, which is quantitatively the most important H+-extruding mechanism, was found in all cell lines tested, but the activity varied strongly. Possible reasons for the qualitative and quantitative differences in antiport activity are discussed.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1988

Influence of parental knowledge and opinions on 12-month diphtheria, tetanus, and pertussis vaccination rates.

To assess the magnitude and cause of decreasing diphtheria, tetanus toxoids, and pertussis (DTP) immunization rates, a retrospective cohort study investigated the immunization status against pertussis among 1-year-old children in Utah. Questionnaires were sent to the parents of 2975 children born in June 1985. Parents were asked about each child's DTP immunization status, including the number, type, and dates of the vaccinations, reasons for or against vaccination, and their knowledge of whooping cough and the vaccine. Children were considered adequately immunized against pertussis when they had received three DTP vaccinations by their first birthday. In Utah, the lack of pertussis immunization among young children is a serious problem: greater than 30% of 1-year-old children were not adequately protected. Accurate parental knowledge about the relative risks of vaccination and illness was associated with a greater likelihood for immunization. Although some parents chose to forego the vaccination because they were concerned about its side effects, the most common reason for incomplete immunization was illness at the time the vaccination was to be given. If immunization rates are to improve, health care professionals must not only make an effort to educate the general population regarding the vaccine, but they must also ensure immediate follow-up for immunization when the procedure is delayed.

Attitude to Health↗
PubMed1988

Radioimmunoassay of rat serum inhibin: changes after PMSG stimulation and gonadectomy.

A heterologous inhibin radioimmunoassay (RIA) method has been developed which is highly specific and of sufficient sensitivity to detect inhibin in female and male rat serum. Purified bovine 31 kDa inhibin was used in the generation of the antiserum and following iodination as tracer in the assay. Parallel logit-log dose-response lines were observed between a rat ovarian extract used as standard and serial dilutions of female and male serum and testicular interstitial fluid. The within-assay variation based on index of precision was 0.049 (n = 5) and the between-assay variation (n = 4) was 9.8%. The specificity of the assay was assessed from: (a) the failure of a number of structurally related proteins (activin-A, transforming growth factor-beta (TGF-beta), Müllerian inhibitory substance) as well as inhibin subunits to crossreact (less than 0.5%) in the assay relative to bovine 31 kDa inhibin; (b) nondetectable levels of immunoactivity in the serum of gonadectomised rats; and (c) a close correlation (r = 0.96) between serum levels of in vitro biological and immunological activities from rats following pregnant mare serum gonadotropin (PMSG) stimulation. Similar initial t 1/2 values (14-15 min) of serum inhibin following gonadectomy were obtained in both sexes. This RIA method will be useful in the study of the physiology of inhibin in the female and male rat.

Animals↗
PubMed1988

Comparative plasma concentration profiles after i.v., i.m. and rectal administration of pethidine in children.

Plasma concentration-time curves of pethidine and norpethidine were studied in 25 children allocated after operation to three groups to receive pethidine 1 mg kg-1 i.v., i.m. or rectally. Peak concentrations occurred after 5 +/- 1, 10 +/- 2, and 60 +/- 10 min, respectively, while the maximum concentrations amounted to 2800 +/- 462, 1609 +/- 367 and 531 +/- 179 nmol litre-1, respectively. The area under the curve (0-240 min) was similarly reduced in the group with rectal administration (P less than 0.05). Compared with the i.v. data, approximately 40% systemic availability occurred after rectal application, although considerable individual variation was noted. In one child very high plasma concentrations were observed after rectal administration, possibly as a result of redistribution/recirculation phenomena. The average results are similar to those obtained when other opioids are given rectally.

Administration, Rectal↗
PubMed1988

Alternative routes for angiotensin-I conversion: kinetics of the renin-angiotensin system in mouse plasma.

Angiotensin-I in plasma may be converted to angiotensin-II or alternatively metabolized through other routes. The aim of the present work has been to quantitate the role of the alternative routes in mouse plasma. A kinetic model for metabolism of the angiotensins through the renin-angiotensin system is proposed, the model allows for alternative routes and for simultaneous reactions to occur. Exogenously added angiotensin-I and angiotensin-II, or endogenously formed angiotensin-I and angiotensin-II from the action of exogenously added renin, were measured in plasma with time. The concentrations of angiotensin-I and angiotensin-II were measured by radioimmunoassay after separation by Dowex cation exchange and HPLC reverse-phase chromatography. The rate constants for the enzymatic reactions were experimentally determined and fitted to the kinetic model. The data were incompatible with a quantitative conversion of angiotensin-I to angiotensin-II, and indicate that about half of the angiotensin-I formed in plasma is metabolized in plasma through alternative routes.

Angiotensin I↗
PubMed1988

Slowing of the heart during anaphylactic shock. A report of five cases.

Five patients are reported with anaphylactic shock reactions due to i.v. administration of atracurium, methicillin, amidotrezoate (n = 2) and plasma. In these patients a fall in heart rate (HR) from 5-50 beats.min-1 was recorded during the hypotensive period. In three of the patients HR was 40 beats.min-1 or less, and in two of the patients a hypotensive bradycardiac episode spontaneously reappeared after normal HR and BP were established. Central venous pressure (CVP) fell in one patient from 0.8 to 0.6 kPa as HR and BP decreased while arterial oxygen tension remained normal. All patients were in a stable condition after treatment with volume expansion and sympathomimetic drugs. These observations indicate that anaphylactic shock is associated with a strong and sometimes persistent vagal tone to the heart in parallel with the early reaction to hypotensive hypovolaemic shock.

Aged↗
PubMed1987

Binding of renin and angiotensinogen to macromolecules in plasma studied by sedimentation equilibrium centrifugation.

Plasma from normal and aggressive mice was subjected to sedimentation equilibrium centrifugation in an air-driven centrifuge. The aim was to study the apparent molecular weight of renin and angiotensinogen in undiluted plasma. Both renin and angiotensinogen appeared heterogeneous with respect to molecular size, suggesting binding to plasma macromolecules. Subsequent high pressure liquid chromatography, using a size exclusion column, demonstrated molecular homogeneity and molecular weights as found in noncentrifuged plasma, indicating that the binding is easily reversible. It is concluded that renin and angiotensinogen in undiluted and unfractionated plasma are weakly bound to plasma macromolecules. This may reduce their activity and to some extent explain the previously observed apparent inhibition of the enzymatic activity.

Aggression↗
PubMed1987

Late appearance of arterial injury caused by fracture of the neck of the humerus.

A 65-year-old man sustained a fracture of the humeral neck. Four days later he suddenly developed symptoms of occlusion of the axillary artery. The fracture was reduced and fixated and the torn intima occluding this artery was fixated. Clots were removed with a Fogarty balloon catheter. Late appearance of arterial injury is rare and we found no reports of this complication after fracture of the humeral neck.

Aged↗
PubMed1986

Is angiotensinogen a renin inhibitor and not the substrate for renin?

The cleavage of the angiotensinogen molecule by renin is slow. The rate constant for cleavage of the enzyme-substrate complex, Kcat (turnover number) is lower than usual for enzymes (0.6/s for the homologous human renin reactions and 0.15/s for the homologous mouse renin reaction). Thus each round of catalysis occurs in 1.7 s in the human and 6.7 s in the mouse reaction. The Kcat/Km values (10(4)-10(6) l/mol per s; Km, Michaelis constant) are high and in the range for protein inhibitors. The association constants (Ka) are (10(6)-10(7) l/mol) close to that of inhibitors. The slow rate seems to be favourable since homologous reactions are slower than heterologous. Angiotensinogen is structurally related to alpha1-antitrypsin. We conclude that kinetic as well as structural data indicate that angiotensinogen might be considered a protease inhibitor for renin.

Angiotensinogen↗