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Biomedical subjects

B Jakobsson

Publications and source records attributed to B Jakobsson.

At least 55 records · Page 3Linked to original sources

Hip fracture incidence in Lund, Sweden, 1966-1986.

The hip fracture incidence in the city of Lund and its rural surroundings was studied for the years 1966, 1972, 1981, and 1986. The total incidence increased from 3.3 to 5.1 per 1,000 inhabitants above 50 years of age. For persons more than 80 years old, the incidence almost doubled from 13.2 to 25.5, i.e., this group represented the entire increase in incidence. In the urban population, men with cervical fractures had an increased incidence. A smaller increase in incidence for both men and women was found in the rural area. Compared with larger cities, the incidence increase in the urban population in Lund was lower over time, but in 1986 the figures were comparable to those in Gothenburg in 1981. The total incidence in the mixed urban and rural population was as of 1981 higher than in Denmark and Finland, but lower than in Norway. If the incidence in the elderly continues to increase to 1995, there will be three times as many hip fractures as there were in 1966.

Adult↗

Mitotic response to high protein intake in different renal cell types in weanling rats.

We examined the effect of high protein intake on the mitotic response (3H-thymidine incorporation) in the glomerulus, proximal tubule (PT), thick ascending limb of Henle (TAL), distal tubule (DT) and collecting duct (CD) in kidneys from 16- to 24-day-old rats that received an isocaloric diet containing 21% (NP) and 50% (HP) protein from 16 days of age. Nephron filtration rate was also determined. After two days of HP diet, thymidine incorporation (TI) was significantly increased in PT and TAL. After two days on HP diet TI was most pronounced in TAL. After eight days on HP diet TI remained elevated in PT, but not in TAL. HP did not increase TI in DT or CD. The glomerular TI was the same in HP as in NP rats after two and four days on the diet, but was significantly elevated after eight days on HP diet. The nephron filtration rate was increased after two days and remained significantly elevated after eight days on HP diet. The proximal tubule fractional reabsorption was the same in 24-day-old NP and HP rats. We conclude that the results are compatible with the hypothesis that the Na load is a major factor triggering tubular growth after HP intake. Glomerular growth is secondary to increase in nephron filtration rate.

Animals↗

Influence of different protein intake on renal growth in young rats.

We have examined the effect of high protein intake on kidney growth and function in growing rats. The rats were kept on an isocaloric diet containing 12%, 21% and 50% protein, from weaning (16 days) until the time of investigation (18, 20, 24, 40 or 80 days). There was no significant difference between the 12% and 21% protein groups in any of the parameters studied. 50% protein increased body weight (BW) and kidney weight (KW). The increase in kidney weight was already evident after 2 days and exceeded the increase in body weight in all age groups. At 24 days renal cortical DNA and the protein/DNA ratio were significantly increased in the 50% protein group. At 40 days the cortical DNA content, but not the protein/DNA ratio, was significantly increased in the 50% group. The glomerular filtration rate GFR) was studied at 40 days. Total GFR as well as GFR/BW was significantly higher in the 50% group than in the 21% group. In one protocol the diet was discontinued at age 40 days and the rats were studied at age 80 days. In these rats all parameters of renal size and function were the same as in the rats that had had a normal (21%) protein intake from weaning. We conclude that in young rats high protein intake reversibly increases GFR out of proportion to BW and selectively and reversibly stimulates kidney growth by stimulating cell proliferation.

Amino Acids↗

IgG and IgM antibody responses to pneumococcal vaccination in splenectomized children and in children who had non-operative management of splenic rupture.

The IgG and IgM type specific anticapsular pneumococcal antibody titres were studied with ELISA during one year following vaccination with a 14-valent pneumococcal polysaccharide vaccine in four different patient groups: 41 children splenectomized after a traumatic rupture, 16 splenectomized because of disease, 15 non-surgically managed after splenic rupture, and 19 healthy controls. Serum samples were obtained before vaccination and after 14, 60, 180, and 360 days. The IgG antibody responses were equally good in all of the patient groups, while the IgM antibody responses were less pronounced in the splenectomized. In the non-surgically managed patients, the IgM antibody titres after vaccination, as well as antibody responses per se, were significantly higher for all 12 pneumococcal types studied than in the patients who were splenectomized. Both the IgG and the IgM antibody titres were highest at 14 days after vaccination. However, while the IgG titres for most pneumococcal types remained elevated at 360 days, the IgM titres soon fell to prevaccination levels. The antibody response was less good for the types 3 and 6 A. The results indicate that the IgG antibody response to pneumococcal polysaccharide vaccination is unaffected in splenectomized individuals, but the IgM antibody response is decreased. In patients with a healed traumatically damaged spleen, both the IgG and IgM responses seem to be normal.

Adolescent↗

Influence of age on compensatory renal growth in rats.

Rats were nephrectomized (nx) or sham-operated (s) at the age of 5 days (young) or 55 days (adult). Nx and s rats from the same litters were studied at various times 5-75 days after surgery with determination of kidney weight and of renal cortical DNA and protein content. In some protocols protein and DNA content were determined in a more homogeneous population of proximal tubular cells. In s rats body weight, kidney weight, renal cortical DNA content, and protein/DNA ratio increased until at least 80 days of age. Body growth was the same in nx and s rats. In young nx rats the remnant kidney was significantly enlarged 5 days after surgery. The difference in kidney size between nx and s rats increased continuously at least until the age of 80 days. The remnant kidney was 125 +/- 9% enlarged 3 wk after nx and 175 +/- 18% enlarged 8 wk after nx. Five days after nx there was no increase in cortical DNA content but a significant increase in protein/DNA ratio. From 2 wk after nx on, the DNA content was significantly higher in nx than in s rats but the protein/DNA ratio was the same in nx and s rats. In adult nx rats, the remnant kidney was enlarged to the same extent 3 and 8 wk after surgery (130 +/- 7 and 132 +/- 8%, respectively). The increase in kidney weight 8 wk after nx was significantly smaller in adult than in young rats. The cortical DNA content and protein/DNA ratio were both moderately but significantly increased in adult rats 8 wk after nx. In conclusion this study has established age-dependent differences regarding the degree, the nature and the duration of compensatory renal growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Serum opsonic activity after pneumococcal vaccination in splenectomized individuals as measured by a nitroblue tetrazolium (NBT) reduction micromethod.

19 children who were splenectomized after traumatic rupture and 15 healthy siblings were vaccinated with a 14-valent pneumococcal vaccine (Pneumovax). The serum opsonic activity against types 3, 6A, 7F, 14, 19F and 23F was evaluated before the vaccination and after 2 and 12 months by a new micromethod based on nitroblue tetrazolium reduction of granulocytes. Before the vaccination, opsonic activity was found more often in the splenectomized than in the controls, 38 and 29%, respectively. However, patients and controls responded similarly to the vaccine. The serum opsonic activity changed from negative to positive after vaccination in 31% of the splenectomized, as well as the controls. The results indicate that the protection against pneumococcal infection after vaccination may not be adequate against all pneumococcal types in all patients.

Adolescent↗

Pulmonary leiomyosarcoma appearing as a cyst. Report of one case and review of the literature.

We describe a case of pulmonary sarcoma appearing as a cyst in the lower lobe. A review of the literature on cavities and malignancies of the lung shows that lung cavities with a wall thickness of 4 mm or less were benign in 92% of the cases. After investigation, a basal segmentectomy was performed in the belief that the lesion was benign. Surprisingly, the histological examination demonstrated spindle-shaped tumor cells, and electron-microscopic studies showed myofilaments suggesting a leiomyosarcoma. This case report illustrates the diagnostic difficulties with lung cavities.

Cysts↗

Nucleic acid labeling with [3H]orotic acid and nucleotide profile in rats in protein deprivation, enteral and parenteral essential amino acid administration, and 5-fluorouracil treatment.

Rats were fed a 0% casein diet for 1 week, with or without enteral or parenteral administration of essential amino acids, or a 25% casein diet, in one group supplemented with 5-fluorouracil treatment. Ninety minutes before sacrifice the rats were given a tracer of [3H]orotic acid. Incorporation into the acid soluble fraction, RNA, and DNA was determined in liver, small intestine, bone marrow, and kidney. Nucleotide profile was examined in liver and intestine. Protein deficiency caused inter alia a decrease in body weight; a decrease in RNA/DNA ratio and an increase in the specific RNA labeling in liver and kidney; an altered nucleotide profile in the liver; an increase in the nucleotide/DNA and RNA/DNA ratios and a decrease in the specific labeling of the acid soluble fraction, RNA, and DNA in the bone marrow. These changes were prevented to the same extent by giving essential amino acids, either orally or intravenously. The minor changes in intestinal nucleotide profile in protein deprivation were prevented to a slightly larger extent by amino acids orally than parenterally. 5-Fluorouracil treatment gave a decrease in the RNA/DNA ratio in the liver and kidney but an increase in the nucleotide/DNA and RNA/DNA ratios in the bone marrow. Nucleotide profiles were unaltered. The amount of DNA per gram of tissue decreased in bone marrow and increased in kidney. Parenteral administration per se resulted in almost no changes.

Amino Acids↗

Hepatic vascular occlusion combined with adriamycin given by the hepatic artery in rats with adenocarcinoma in the liver.

Rats with an adenocarcinoma of the colon implanted into the liver were treated by a bolus injection of adriamycin by the hepatic artery. In addition, vascular occlusions were performed in the following three ways. 1. The hepatic artery was ligated (HAL) immediately after adriamycin injection. 2. The portal venous branch nourishing the tumor was ligated immediately after adriamycin injection. 3. The Pringle maneuvre (clamping of the hepatic artery, the portal vein and the common bile duct) was performed during 5 min before and 10 min after injection. Tumor size was measured at operation and 6 and 12 days later in the first experiment, 7 days later in the other two experiments. The combination of adriamycin and HAL retarded tumor growth at day 6 as compared to controls, adriamycin alone and HAL alone. The differences were not significant at day 12. The other vascular occlusions did not improve the antitumor effect of adriamycin.

Adenocarcinoma↗

Tumour antigen heterogeneity within melanoma metastases--an evaluation by immunohistochemistry.

Fifty-eight metastases of malignant melanoma in 27 consecutive patients were evaluated by immunohistochemistry using monoclonal antibodies (MAb) 96.5, 48.7 and 4.2, all with a high specificity for melanoma tumour associated antigens. MAb OKT3 directed to human T-lymphocytes was used as control and normal mouse serum as background. Different degrees and patterns of staining were recorded using a scale of 0 to 4. 85% of the metastases were positive (score greater than +2) to 96.5 or 48.7 and 78% to antibody 4.2. All metastases were positive for at least one of the three antibodies, 93% for two, and 59% for all three antibodies. No substantial heterogeneity (more than +1 difference) was found in two sections approximately 5 mm apart within the same metastasis (one out of 39 metastases). In 15 patients in whom more than one tumour was examined, heterogeneity between individual metastases was found in one patient for antibody 96.5, three for 48.7 and none for 4.2. The existence of immunological heterogeneity in melanoma metastases must be taken into account when designing techniques for radioimmunoimaging and radioimmunotherapy.

Antibodies, Monoclonal↗

Incorporation of 5-fluorouracil into RNA of normal tissues and an adenocarcinoma in protein-deprived rats.

One of the main cytotoxic effects of 5-FU is its incorporation into RNA. In rats, protein deprivation increases the incorporation of labelled precursors into liver RNA. We examined the effect of protein deprivation on the incorporation of a therapeutic dose of 5-FU into the liver, small intestine, kidney and bone marrow and into an adenocarcinoma transplanted to the liver in the rat. The rats were fed either on a 25% or a 0% casein diet for one week. Some rats from both groups were given amino acids or glucose parenterally. Therapeutic 5-[3H]-FU was given in a 2 h infusion by the hepatic artery and the rats were sacrificed one h later. Incorporation into liver and intestinal RNA increased significantly with protein deprivation. The increase was largely eliminated by parenteral feeding of amino acids. No differences were found in incorporation into tumor and bone marrow RNA in protein deprivation. Incorporation into the acid soluble fraction and DNA is also reported.

Adenocarcinoma↗

Modulation of 5-fluorouracil toxicity by uridine, deoxyuridine, orotate and dipyridamole in normal tissues of rats with liver adenocarcinoma.

The cytotoxicity of 5-FU, given by the hepatic artery, was measured by its incorporation into the acid soluble fraction, RNA and DNA in normal tissues and an adenocarcinoma transplanted into the liver in rats. Other substances were simultaneously administered by the portal vein to modulate the cytotoxicity. None of them had any significant influence on the incorporation of 5-FU into tumor. Dipyridamole decreased the incorporation of 5-FU into liver RNA and increased the nucleotide/DNA and RNA/DNA ratios so that the incorporation into mg RNA per liver cell was unchanged. Dipyridamole decreased the incorporation into the acid soluble fraction, RNA and DNA of the small intestine and also into RNA per mg DNA. It increased the nucleotide/RNA and RNA/DNA ratios in the bone marrow. Orotate decreased the incorporation into liver and intestinal RNA. Uridine increased the incorporation into liver RNA. The results obtained with dipyridamole were the most pronounced. Studies are continuing with this and other membrane transport inhibitors.

Adenocarcinoma↗