Biomedical subjects

H Lilja

Publications and source records attributed to H Lilja.

170 records · Page 10Linked to original sources

PubMedDate not supplied

Immunohistochemical and in situ hybridization studies of beta-microseminoprotein in the human gastric mucosa.

beta-Microseminoprotein is a 10-kDa disulphide-rich protein with unknown function which is present in the mucus of the airways, gastrointestinal tract and urogenital tract. In this paper, an investigation of the distribution of beta-microseminoprotein in the human stomach is reported. Immunohistochemistry and in situ hybridization were used. beta-Microseminoprotein was found to be localized mainly in the antrum part of the stomach and in two types of cells. Cells of the most abundant type (designated M-cells) were the neutral mucin-containing cells in the bottom part of the gastric glands and the surface epithelium. Virtually all these cells contained both beta-microseminoprotein mRNA and protein product. Cells of the second type (designated E-cells) were found in a zone one-third up from the bottom of the gastric glands, where gastric endocrine cells are located. The E-cells were fewer than the M-cells and usually solitary. They seemed to have a high concentration of protein compared with their low mRNA level. The majority of the E-cells contained chromogranin A and gastrin. The observations made have implications for the understanding of the differentiation of the mucosal cells in the antrum of the stomach and form a basis for future studies of beta-microseminoprotein in gastric disease.

DNA, Complementary↗

PubMedDate not supplied

Response of cultured fetal and adult rat hepatocytes to growth factors and cyclosporine.

Hepatocyte transplantation is a promising alternative to orthotopic liver transplantation in experimental animal models with genetic disorders of liver metabolism and liver failure. Fetal hepatocytes have several characteristics that make them potentially suitable as donor cells. In contrast to adult hepatocytes, fetal hepatocytes are thought to be highly proliferative, which may facilitate engraftment, expansion of transplanted cell population, and gene transfer requiring active DNA synthesis. The present study was undertaken to evaluate the proliferative capacity of fetal and adult rat hepatocytes under standardized culture conditions. Fetal (20 days of gestation) and adult hepatocytes were cultured in serum-free media at low densities and treated with growth factors. Proliferation was assessed by [3H]-thymidine incorporation and cell cycle analysis by flow cytometry. In nonstimulated cells, DNA synthesis at 4 h was about x100 higher and after 10 days in culture x20 higher in fetal compared to adult hepatocytes. When epidermal growth factor (EGF) was added, maximal DNA synthesis in fetal hepatocytes was seen at 48 h, whereas in adult hepatocytes at 72 h. For adult hepatocytes, the average increase compared to untreated cells was x13.8 with EGF, x18.5 with transforming growth factor alpha (TGF-alpha), and x7.6 with hepatocyte growth factor (HGF). For fetal hepatocytes, the increase was twofold with either EGF, TGF-alpha or HGF. EGF-, TGF-alpha- and HGF-dependent DNA synthesis was inhibited by transforming growth factor beta-1 (TGF-beta1) in both fetal and adult hepatocyte cultures; this antiproliferative effect was significantly stronger in adult hepatocyte cultures. With cyclosporine, EGF-, TGF-alpha- and HGF-dependent DNA synthesis in fetal hepatocyte cultures decreased by 36-46%, whereas in adult hepatocytes by 19-27 %. These results show that in contrast to adult hepatocytes, fetal hepatocytes have high spontaneous proliferative activity independently of growth factors and are relatively resistant to the inhibitory effect of TGF-beta1. It was also found that cyclosporine suppresses proliferation of cultured fetal hepatocytes.

Animals↗

PubMedDate not supplied

Transplantation of hepatocytes for prevention of intracranial hypertension in pigs with ischemic liver failure.

Intracranial hypertension leading to brain stem herniation is a major cause of death in fulminant hepatic failure (FHF). Mannitol, barbiturates, and hyperventilation have been used to treat brain swelling, but most patients are either refractory to medical management or cannot be treated because of concurrent medical problems or side effects. In this study, we examined whether allogeneic hepatocellular transplantation may prevent development of intracranial hypertension in pigs with experimentally induced liver failure. Of the two preparations tested--total hepatectomy (n = 47), and liver devascularization (n = 16)--only pigs with liver ischemia developed brain edema provided, however, that animals were maintained normothermic throughout the postoperative period. This model was then used in transplantation studies, in which six pigs received intrasplenic injection of allogeneic hepatocytes (2.5 x 10(9) cells/pig) and 3 days later acute liver failure was induced. In both models (anhepatic state, liver devascularization), pigs allowed to become hypothermic had significantly longer survival compared to those maintained normothermic. Normothermic pigs with liver ischemia had, at all time points studied, ICP greater than 20 mmHg. Pigs that received hepatocellular transplants had ICP below 15 mmHg until death; at the same time, cerebral perfusion pressure (CPP) in transplanted pigs was consistently higher than in controls (45 +/- 11 mmHg vs. 16 +/- 18 mmHg; p < 0.05). Spleens of transplanted pigs contained clusters of viable hepatocytes (hematoxylin-eosin, CAM 5.2). It was concluded that removal of the liver does not result in intracranial hypertension; hypothermia prolongs survival time in both anhepatic pigs and pigs with liver devascularization, and intrasplenic transplantation of allogeneic hepatocytes prevents development of intracranial hypertension in pigs with acute ischemic liver failure.

Animals↗

PubMedDate not supplied

Measurement of prostate-specific antigen and human glandular kallikrein 2 in different body fluids.

It has been demonstrated that prostate-specific antigen (PSA), in spite of its name, can be detected in body fluids and tumors from a variety of organs. Investigations have shown that human glandular kallikrein 2 (hK2), a related prostate-secreted protease, can activate the zymogen form of PSA, suggesting that the two enzymes might work as a functional unit, with hK2 as the activator molecule and PSA as the effector molecule. If this is true, then hK2 should be found together with PSA in body fluids other than seminal plasma, as well. Recently, a sensitive and specific assay was devised for hK2, enabling its measurement in picogram quantities. With this assay, the concentration of hK2 was determined in samples of seminal plasma, amniotic fluid, breast milk, and saliva. Simultaneously, the samples were assayed for molecular forms of PSA. In seminal plasma, the mean PSA concentration was 0.82 mg/ml, while the hK2 level was around two orders of magnitude lower: mean value, 6.4 microg/ml. Approximately the same ratio of PSA to hK2 as in seminal plasma was found in amniotic fluid and breast milk, but in most samples, the hK2 values were too low for direct measurements and had to be concentrated prior to analysis. Measurable levels of PSA, all in the free form, were detected in amniotic fluid at the thirteenth week of gestation and then gradually increased to levels around and over 1 microg/L from the twentieth week. Significant levels of PSA were detected in amniotic fluid collected at delivery, also. Measurable levels of mammary PSA were primarily detected in colostrum, with a range from less than 0.03 microg/L to 2.1 mg/L. Around half of the molecules were in complex with protease inhibitor. Most surprisingly, determinations on saliva samples showed that none of them had detectable PSA levels but had measurable concentrations of hK2 with a mean value, 0.09 microg/L. The presence in saliva suggests that hK2 can be the human equivalent to one of the mouse salivary kallikreins with important biological function, like the epidermal growth factor-binding protein or the gamma subunit of nerve growth factor. However, this was ruled out, as a phylogenetic analysis showed that the human and mouse glandular kallikreins evolved independently from a common precursor after the separation of the primate and rodent lineages. In conclusion, the measurements show that in addition to the previously known secretion in seminal plasma, hK2 is secreted in amniotic fluid, breast milk, and saliva. Furthermore, the concerted expression of PSA and hK2 in seminal plasma, amniotic fluid, and breast milk suggests that the two proteases might form a functional unit but not always as demonstrated by the sole presence of hK2 in saliva.

Amniotic Fluid↗

PubMedDate not supplied

Gastricsin-mediated proteolytic degradation of human seminal fluid proteins at pH levels found in the human vagina.

The proteolytic degradation of human seminal fluid proteins at acidic conditions has been investigated. Upon acidification to the pH level of the human vagina, autoproteolysis of most seminal fluid proteins occurred after 30 minute of incubation at 37 degrees C. The degradation was unaffected by inhibitors of serine, thiol, or metallo proteases, whereas pepstatin prevented any proteolysis. The proteins in seminal fluid depleted of the aspartic protease progastricsin did not degrade upon acidification. Readdition of the progastricsin restored the autoproteolytic ability of seminal fluid. Prostate-specific antigen, prostatic acid phosphatase, and Zn-alpha 2-glycoprotein are quickly degraded; albumin, transferrin, and lactoferrin are degraded more slowly. The low molecular weight fragments of semenogelin I and II and especially beta-microseminoprotein are somewhat resistant to proteolysis. These observations strongly suggest that the aspartic protease progastricsin is responsible for the autoproteolysis of seminal fluid proteins under acidic conditions. This suggests that the function of the enzyme is to degrade seminal fluid proteins deposited in the vagina; this in turn may decrease the antigenic load in the vagina and prevent immuno-infertility.

Acid Phosphatase↗

PubMedDate not supplied

Secretory leucocyte protease inhibitor in the male genital tract: PSA-induced proteolytic processing in human semen and tissue localization.

Secretory leucocyte protease inhibitor, SLPI, is a low-molecular-weight, acid-stable protein present in the liquid part of fresh human ejaculate but not demonstrable in the gel structure. No fragmentation of SLPI occurred during gel dissolution, but a slow proteolytic cleavage of SLPI was seen on incubation of the liquified semen at 37 degrees C. The same pattern of degradation products was seen after incubation of SLPI with prostatic secretion and also with purified prostate-specific antigen, PSA. We could identify Arg 20-Tyr 21 and Met 73-Leu 74 to be the primary cleavage sites upon proteolytic modification of SLPI by purified PSA. However, we did not find any inhibition of the enzymatic activity of PSA by SLPI, even at a 100-fold molar excess of the inhibitor. The slow degradation of SLPI facilitated sampling and the reliable determination of the normal level of SLPI in seminal plasma, which was about 20 mg/L. We investigated the glandular origin of SLPI in the genital tract by immunocytochemistry. A strong immunostaining for SLPI was demonstrated in epithelial cells within the glandular lumina of the prostate gland, seminal vesicles, and epididymis but not in the stromal parts of these glands. In addition the immunostaining was also detected in the deferent ducts and the germinal epithelium of the testes. Taking into account that SLPI is a strong inhibitor of several proteases, including leukocyte elastase and cathepsin G, the results suggest that SLPI has a local protective function against proteolytic degradation of the male reproductive tract tissues during inflammation.

Amino Acid Sequence↗

PubMedDate not supplied

Distribution and tissue expression of semenogelin I and II in man as demonstrated by in situ hybridization and immunocytochemistry.

Semenogelin I and II (Sgl, Sgll) are two separate gene products of chromosome 20 with extensive (80%) identity in primary structure. They are mainly responsible for immediate gel formation of freshly ejaculated semen. Degradation of Sgl and Sgll is due to the proteolytic action of prostate-specific antigen (PSA); it results within 5-15 minutes in liquefaction of semen and release of progressively motile spermatozoa. By means of cDNA cloning and Northern blots, Sgl and Sgll transcripts have previously been shown to be abundant in human seminal vesicles, but Sgll alone is suggested to be expressed at low levels in the epididymis. To characterize the expression and tissue distribution of Sgl and Sgll in greater detail, we produced monoclonal immunoglobulin Gs (lgGs for immunocytochemistry (lCC) and specific [35S]-, digoxigenin-, or alkaline phosphatase-labeled 30-mer antisense probes to Sgl and Sgll for in situ hybridization (lSH). Immunocytochemical staining for both Sgl and Sgll, and lSH detection of both Sgl and Sgll transcripts, were demonstrated in the cytoplasm of seminal vesicle epithelium. lSH showed Sgll alone to be expressed in the epithelium of the epididymal cauda. Neither lCC nor lSH yielded any evidence of Sgl or Sgll expression in caput or corpus epithelium or in any stromal cells of the epididymis. Consistent with our previous findings using polyclonal lgG, monoclonal anti-Sgll Sgll lgGs identified epitopes on the posterior head, midpiece, and tail of ejaculated spermatozoa. Spermatozoa in the epididymal cauda were also immunoreactive, but those in the caput or corpus region of the epididymis as well as those in the testis were negative. As shown by lCC, neither Sgl nor Sgll were expressed in the testis, the prostate, the female genital tract, or other normal human tissue specimens. Although the significance of Sg attachment to epididymal and ejaculated spermatozoa remains to be established, monoclonal anti-Sg lgG might prove useful in establishing the origin of seminal vesicle tissue components in prostate core biopsies or other biopsy specimens.

Aged↗

PubMedDate not supplied

Impaired secretory function of the prostate in men with oligo-asthenozoospermia.

The secretory function of the human prostate and the seminal vesicles is a prerequisite for gel formation and liquefaction of semen, but the relation to poor sperm motility and low sperm count in infertile men remains to be clarifyed. Our aim was to evaluate the secretory function of the prostate and the seminal vesicles in normozoospermic men (n = 35) and in asthenozoospermic men, who were all also oligozoospermic (n = 27). All 62 subjects belonged to couples undergoing routine infertility evaluation. In liquefied seminal fluid we measured the concentrations of fructose and protein C inhibitor (PCI) contributed by the seminal vesicles, PCI complexed to prostate-specific antigen (PSA), and the prostatic contribution of zinc, PSA, acid phosphatase (PAP), beta-microseminoprotein (beta-MSP), and Zn alpha 2-glycoprotein (Zn alpha 2-GP). The concentration of each prostatic secretory protein correlated significantly with that of zinc (P < 0.01) in both the normozoospermic (NZS) and oligo-asthenozoospermic (OAZS) subgroups, but the PCI concentration did not correlate significantly with that of fructose. There was no significant difference between the NZS and OAZS subgroups in ejaculate volume or secretory contribution from the seminal vesicles, whereas the OAZS subgroup was characterized by significantly lower secretory contributions of Zn alpha 2-GP (P = 0.001), Zn, PSA, PAP (P < 0.01), and beta-MSP (P < 0.05). The two subgroups did not differ significantly in the serum concentration of luteinizing hormone (LH), testosterone, or sex hormone-binding globulin (SHBG). The results thus suggest the secretory contribution of major prostatic proteins and zinc per ejaculate to be significantly decreased in oligo-asthenozoospermic men. The importance of this finding in relation to poor sperm count and motility as indicators of impaired gonadal function requires further investigation.

Adult↗