Biomedical subjects

J Jensen

Publications and source records attributed to J Jensen.

At least 595 records · Page 33Linked to original sources

PubMed1976

Current determination of lithium-induced minimum sodium requirement in rats.

Lithium administration raises the minimum sodium requirement of the organism. Lithium treated-rats drink spontaneously a hypertonic sodium chloride solution and thereby protect themselves against the toxic effects of lithium. In the present paper it was studied whether the consumption of sodium chloride can be used as a quantitative measure of the sodium requirement. Rats given different amounts of lithium with food for about 2 months were given free access to water and a 0.46 M NaCl solution, and the 24-h intake of the latter was followed. It was found that the consumption of hypertonic sodium chloride increased with the lithium dosage and the serum lithium level. The consumption showed the following characteristics: (a) It was sufficient to prevent death from lithium poisoning. (b) When access to hypertonic chloride was discontinued for 48 h, the rats lost body weight; the body weight was reestablished within 1 h when the rats again had access to sodium chloride solution. (c) When sufficient amounts of sodium were given with the food, the lithium-treated rats drank no more sodium chloride solution than did the control rats. (d) When lithium administration was discontinued, the consumption of sodium chloride solution fell within 10 days to the control level. (e) The lithium-treated rats developed polyuria, but this was not the cause of the extra intake of sodium chloride. (f) The lithium-treated rats did not drink more of the hypertonic sodium chloride solution than was necessary to cover the minimum sodium requirement. The results indicate that the intake of hypertonic sodium chloride solution can, in fact, be used as a measure of the minimum sodium requirement in lithium-treated rats.

Animals↗

PubMed1976

Chromosome studies in "preleukemia". III. Myelofibrosis.

Cytogenetic studies were done on 18 patients with myelofibrosis or the closely related syndrome, undifferentiated myeloproliferative disorder (MPD). Clones of cells with chromosome abnormalities were demonstrated in the blood of eight individuals, including two with a history of radiation therapy and two with "acute myelofibrosis". Trisomy 8 was present in the latter two patients, but otherwise, there was no consistent cytogenetic pattern or correlation with specific hematologic findings. Sixteen of these patients have been followed for more than 1 year or until death; none has progressed to leukemia. The results indicate that chromosome abnormalities are relatively common in this disorder, but as with polycythemia vera, and unlike some other "preleukemic" states, the aberrant clones in myelofibrosis do not appear to indicate that clinical leukemia is imminent.

Adolescent↗

PubMed1976

T cell variant of chronic lymphocytic leukaemia with chromosome abnormality and defective response to mitogens.

Lymphocytes from a patient with chronic lymphocytic leukaemia, in whom therapy was ineffective, were defined as thymus-derived (T) cells by membrane markers (sheep erythrocyte rosettes, complement rosettes, surface immunoglobulin). The lymphocytes responded weakly to two mitogens, phytohaemagglutinin and the calcium ionophore A23187, but not to concanavalin A. Cytogenetic studies of leukaemic cells from unstimulated and mitogen-stimulated cultures revealed an abnormal karyotype with 45 chromosomes and multiple rearrangements. The T cell variant of classical chronic lymphocytic leukaemia is relatively rare; additional reports are needed to determine if the clinical course is typically less benign than in the common B cell variety, or whether this patient simply represented a late, unresponsive phase of the disease.

Aged↗

PubMed1976

A comparison of Mersilene and polyglycolic acid sutures in pararectal abdominal wounds after appendectomy.

A total of 206 patients were subjected to operation for acute appendicitis through a pararectal laparotomy. Mersilene was used in 101 and polyglycolic acid (PGA, Dexon) in 105 patients as buried sutures for the closure of the abdominal wall, including the fascial layer. Wound complications developed after Mersilene in 23 and after PGA in 10 cases. PGA did not lead to an increased frequency of early wound infections. Granulomata or fistulae developed after Mersilene in 18 patients, but not in any of the cases in which PGA was used. Wound rupture and incisional hernia did not occur in any of the patients in the two groups.

Appendectomy↗

PubMed1976

Effect of prolonged lithium ingestion on the response to mineralocorticoids in rats.

The effect of long-term lithium administration on the response to mineralocorticoids was studied in rats which were adrenalectomized in order to avoid the effects of endogenous hormone. The hormone response was estimated from the changes in urinary excretion of sodium and potassium in rats on low and high sodium intake and from the consumption of a hypertonic NaCl solution by rats given a free choice between this and demineralized water. Lithium was found to lower the response to aldosterone and deoxycorticosterone acetate both in acute and chronic experiments. It was further found that in adrenalectomized rats given no hormone, those given lithium consumed significantly more NaCl solution than those given no lithium. The experiments therefore provide evidence that lithium induces a sodium requirement beyond that induced by the inhibition of the response to mineralocorticoids.

Adrenal Glands↗

PubMed1975

The narrow vestibular aquaeduct. An unspecific radiological sign?

Tomography of the vestibular aquaeduct was carried out in patients with Ménière's disease, patients with chronic otitis and in patients without ear disorders. Visualization of the vestibular aquaeduct was evaluated blindly. The descending part of the aquaeduct was clearly visible in 95% of patients without ear disease. In the other groups, including contralateral non-affected ears in Ménière patients, the aquaeduct was clearly visible in only about 50%. The incidence of narrow or invisible aquaeducts in ducts in Ménière patients and in patients with chronic otitis was essentially the same. This radiologic finding seems to be an unspecific sign, present possibly in a variety of ear disorders.

Adolescent↗

PubMed1975

Two complex translocations in chronic granulocytic leukemia involving chromosomes 22, 9, and a third chromosome.

Among 13 Ph-positive cases of chronic granulocytic leukemia (CGL), banding studies revealed two with complex rearrangements involving translocation of the long arm of number 22 to another autosome and a segment of that chromosome translocated to the long arm of number 9. In a patient with both CGL and sickle cell anemia, the 3-way rearrangement involved chromosomes 5, 9, and 22; and he also had a second Philadelphia chromosome and two constitutional variants: pericentric inversion of the other number 9 chromosome and satellite polymorphism in the G group. The karyotype of the leukemic cells was interpreted as: 47,XY,inv(9) (p11q13),t(5;9;22)(q13;q34;q11)+del(22)(q11). In the second patient, the complex translocation in the Ph-positive cells involved chromosomes 3, 9, and 22, resulting in a karyotype interpreted as: 46,XX,t(3;9;22)(p21;q34;q11). Several reports indicate that an abnormality of chromosome 9 is not essential for the development of Ph-positive CGL, but the very high frequency of its involvement (including these unusual translocations) suggests that some type of non-random somatic association may exist between 9q and 22q which makes simultaneous breakage likely. Attempts to correlate specific types of pH chromosome rearrangements with the clinical course of CGL must await the identification of more cases and longer follow-up.

Adult↗

PubMed1975