Virological response to antiviral therapy at week 12 indicates a great reduction of intrahepatic hepatitis B virus DNA and cccDNA in HBeAg-positive chronic hepatitis B patients

Early virological response is considered to be a predictor for the outcome of anti-hepatitis B virus (HBV) therapy. To analyze its correlation to intrahepatic HBV DNA and covalently closed circular DNA (ccc)DNA, 71 hepatitis B virus e antigen (HBeAg)-positive chronic hepatitis B patients were recruited: 34 patients were treated with lamivudine; 13 with interferon-alpha2b; and 24 with sequential therapy of lamivudine-interferon-alpha2b for 48 weeks. Intrahepatic HBV DNA and cccDNA load were measured at the baseline and at Week 48. Fifty-seven patients had virological response at Week 12. Median decreases of serum HBV DNA in patients with or without virological response at Week 12 were 4.0 log(10) (max. 6.2, min. 2.2) and 1.1 log(10) (max. 2.1, min. 0) (Z = -5.766, P = 0.0000), respectively. At Week 48 they were 4.1 log(10) (max. 7.4, min. 1.0) and 2.3 log(10) (max. 7.5, min. 0.3) (Z = -2.760, P = 0.006), respectively. For intrahepatic HBV DNA load they were 1.3 log(10) (max. 4.3, min. -1.2) and 0.6 log(10) (max. 3.5, min. -0.8), respectively, and for HBV cccDNA load they were 1.1 log(10) (max. 4.8, min. -0.5) and 0.5 log(10) (max. 3.0, min. -0.8) (Z = -2.097, P = 0.036), respectively at Week 48. Step-wise logistic regression analysis indicated that the baseline intrahepatic HBV DNA load effected virological response at Week 12 [odds ratio (OR) 0.405; 95% confidence interval (CI) 0.174-0.944; P = 0.036] and HBeAg seroconversion at Week 48 (OR 0.292; 95% CI 0.131-0.649; P = 0.003). In conclusion, virological response at Week 12 indicated a great reduction of intrahepatic DNA and cccDNA load in HBeAg-positive CHB patients. The baseline intrahepatic HBV DNA load affected virological response at Week 12 and HBeAg seroconversion at Week 48.

Recording Bessel-like beam shapes generated by plasmonics lens

In our study, we spun a negative photoresist layer on top of a plasmonic lens which was formed by adopting a metallic ring structure with a nano-scale width opening. We recorded the beam shape of the Bessel-like beam emitting from the plasmonic lens which formed a high aspect ratio structure. We found that the high aspect ratio structure was higher after exposure as the inner and outer diameter had increased. In addition, we used an oblique incidence on the negative resist metallic ring structure to produce an inclined micro-structure. Different exposure results were obtained with the two different metal thicknesses. Therefore, in our study, we not only proved that it is possible to record the shape of a Bessel-like beam, but we also demonstrated that it is possible to create a plasmonic lens which is capable of creating a high aspect ratio structure through exposure.

Microsatellite instability did not predict individual survival in sporadic stage II and III rectal cancer patients

OBJECTIVES

Tumors with high-frequency microsatellite instability (MSI-H) have unique biological behavior and the predictive role of microsatellite instability (MSI) status on survival of colorectal cancer is still debated. The prognostic significance of MSI status in sporadic stage II and III rectal cancer patients needs to be more precisely defined. So we investigated the relationship between MSI status and clinicopathological features and prognosis in these patients.

METHODS

DNAs from fresh-frozen paired samples of tumors and corresponding normal tissue from 128 stage II and III rectal cancer patients were analyzed for MSI by PCR amplification using markers recommended by a National Cancer Institute workshop on MSI. To assess prognostic significance, Cox proportional hazards modeling was used.

RESULTS

Twelve (9.3%) tumors in our study were MSI-H, 28 (21.9%) were low-frequency MSI (MSI-L) and 88 (68.8%) were microsatellite stable (MSS). Most of the MSI-H tumors compared with MSI-L and MSS tumors were found in female patients (p = 0.031), had mucinous histology (p = 0.023), high grade of differentiation (p = 0.002) and high level of preoperative serum carcinoembryonic antigen (p = 0.005). Rectal cancer patients with MSI-H did not show a better clinical outcome than those with MSI-L/MSS, neither in all cases (p = 0.986) nor in stage II and stage III disease analyzed separately (p = 0.705 and p = 0.664, respectively).

CONCLUSIONS

Data provided here demonstrated there was high incidence of MSI-H and MSI was not a prognostic factor in sporadic stage II and III rectal cancers from the Chinese Han population included in this study. Tumor stage is more suitable than MSI status for prediction of individual survival in sporadic stage II and III rectal cancer patients.

Overexpression of connective tissue growth factor WISP-1 in Chinese primary rectal cancer patients

AIM: To clarify the expression change of Wnt-induced secreted protein-1 (WISP-1) in human rectal cancer and to determine whether it is correlated with invasion and metastasis of human rectal cancer.

METHODS: Eighty-six paired samples of rectal cancer and surgically resected distant normal rectal tissue were collected and allocated into cancer group and control group respectively. WISP-1 mRNA was detected by relative quantitative real-time RT-PCR and WISP-1 protein was examined by immunohistochemical staining.

RESULTS: WISP-1 gene overexpression was found in 65% (56/86) primary rectal cancers, 2-30 times that of the level in normal matched rectal tissues (P = 0.001). The mRNA expression level was correlated with Duke’s staging, histological differentiation grade and lymph node status. The WISP-1 protein expression was in accordance with mRNA expression level. The positive degree of immunohistochemical staining in the cancer group (1.40 ± 0.35) was different from that in control group (1.04 ± 0.08, P < 0.001). Moreover, in cancer group the positive staining degree in high-level mRNA cancers (1.46 ± 0.37, n = 56) was higher than that in low-level mRNA (1.28 ± 0.28, n = 30, P = 0.018).

CONCLUSION: Aberrant levels of WISP-1 expression may play a role in rectal tumorigenesis. WISP-1 may be used as a specific clinical diagnosis and prognosis marker in rectal cancer.

Novel mutations and sequence variants in exons 3-9 of human T Cell Factor-4 gene in sporadic rectal cancer patients stratified by microsatellite instability

AIM: To establish the role of human T Cell Factor-4 (hTCF-4) gene exons 3-9 mutation status in association with sporadic rectal cancer with microsatellite instability (MSI).

METHODS: Microsatellite markers were genotyped in 93 sporadic rectal cancer patients. Eleven cases were found to be high-frequency MSI (MSI-H). Sequence analysis of the coding region of the exons 3-9 of hTCF-4 gene was carried out for the 11 MSI-H cases and 10 controls (5 microsatellite stability (MSS) cases and 5 cases with normal mucosa). The sequencing and MSI identification were used.

RESULTS: Several novel mutations and variants were revealed. In exon 4, one is a 4-position continuous alteration which caused amino acid change from Q131T and S132I (391insA, 392 G > A, 393 A > G and 395delC) and another nucleotide deletion (395delC) is present in MSI-H cases (5/10 and 4/10, respectively) but completely absent in the controls.

CONCLUSION: Novel mutations in exon 4 of hTCF-4 gene were revealed in this study, which might be of importance in the pathogenesis of sporadic rectal cancer patients with MSI-H.

Polymorphisms of short tandem repeat of genes and breast cancer susceptibility

AIM

To explore the relationship of short tandem repeat polymorphisms and breast cancer susceptibility.

METHODS

We searched the MEDLINE database (up to June 2006) with the keywords of tandem repeat sequences, gene polymorphisms, breast cancer, cancer susceptibility and microsatellite instability. We reviewed the literature on gene polymorphisms, especially the relationship of short tandem repeat and breast cancer risk.

RESULTS

We focused on the candidate genes sex hormones, steroid hormone and receptors, carcinogen metabolism, cell proliferation regulation and other genes.

CONCLUSIONS

The functional effects of short tandem repeat polymorphisms on cancer susceptibility, especially on breast cancer risk, are identified. The importance of short tandem repeat polymorphisms on development and progression of breast cancer are discussed.

Homeobox genes and their functions on development and neoplasm in gastrointestinal tract

AIM

To describe the role of homeobox genes on development and tumorigenesis in gastrointestinal tract.

METHODS AND RESULTS

We searched the MEDLINE database (until March, 2006) with the keywords of homeobox genes, gastrointestinal tract, development, tumorigenesis, carcinogenesis and therapeutic targets. We reviewed the literature on classification of homeobox genes, development of gastrointestinal tract, carcinogenesis of gastrointestinal tract as well as therapeutic targets.

CONCLUSIONS

The functional effects of homeobox family in development and tumorigenesis of gastrointestinal tract are identified. The importance of homeobox genes and a possibility of therapeutic intervention in clinical medicine are discussed.

[Effects of antiviral effects of agents and prognosis of chronic hepatitis B.]

BACKGROUND

To analyze the effects of difference antiviral agents and the effects of the treatments on long-term prognosis.

METHODS

Retrospective research method was applied.

RESULTS

About 40% of the patients were treated with interferon or lamivudine. After the treatment, in lamivudine group, the negative rate of HBV DNA was the highest. In the interferon group, the sero conversion rates of HBeAg/HBeAb were 22.9%. In the antiviral treatment patients, the disease progression and the occurrence of cirrhosis and liver cancer were much lower than those of the control groups. The mortality of cirrhosis and liver cancer in the HBeAg/HBeAb sero converted group was much lower than that of the group without HBeAg/HBeAb sero conversion groups (P less than 0.05).

CONCLUSION

The antiviral effects of interferon and lamivudine were better than those of the other drug groups. The antiviral drugs could relieve the disease progression and reduce the mortality of cirrhosis and liver cancer.

NF-κB as a molecular target in adjuvant therapy of gastrointestinal carcinomas

AIM

To describe the role of nuclear factor-kappa B (NF-kappaB) in cancer treatment.

METHODS

We searched the Pubmed database (until Oct, 2004) with the keywords of gastrointestinal carcinoma, NF-kappaB, inhibitor, cancer treatment molecular target and chemoresistance. We reviewed the literature in the role of NF-kappaB activation in chemoresistance, tumour growth suppression and enhancement of apoptosis in gastrointestinal carcinomas.

CONCLUSIONS

Several possible strategies for inhibiting NF-kappaB activation are identified. The importance of targeting NF-kappaB as a potential therapeutic approach in clinical medicine was discussed.

Pathological study of distal mesorectal cancer spread to determine a proper distal resection margin

AIM: Local recurrence after curative surgical resection for rectal cancer remains a major problem. Several studies have shown that incomplete removal of cancer deposits in the distal mesorectum contributes a great share to this dismal result. Clinicopathologic examination of distal mesorectum in lower rectal cancer was performed in the present study to assess the incidence and extent of distal mesorectal spread and to determine an optimal distal resection margin in sphincter-saving procedure.

METHODS: We prospectively examined specimens from 45 patients with lower rectal cancer who underwent curative surgery. Large-mount sections were performed to microscopically observe the distal mesorectal spread and to measure the extent of distal spread. Tissue shrinkage ratio was also considered. Patients with involvement in the distal mesorectum were compared with those without involvement with regard to clinicopathologic features.

RESULTS: Mesorectal cancer spread was observed in 21 patients (46.7%), 8 of them (17.8%) had distal mesorectal spread. Overall, distal intramural and/or mesorectal spreads were observed in 10 patients (22.2%) and the maximum extent of distal spread in situ was 12 mm and 36 mm respectively. Eight patients with distal mesorectal spread showed a significantly higher rate of lymph node metastasis compared with the other 37 patients without distal mesorectal spread (P = 0.043).

CONCLUSION: Distal mesorectal spread invariably occurs in advanced rectal cancer and has a significant relationship with lymph node metastasis. Distal resection margin of 1.5 cm for the rectal wall and 4 cm for the distal mesorectum is proper to those patients who are arranged to receive operation with a curative sphincter-saving procedure for lower rectal cancer.

Germline mutational analysis of CDH1 and pathologic features in familial cancer syndrome with diffuse gastric cancer/breast cancer proband in a Chinese family

AIMS

Hereditary non-polyposis colorectal cancer, thyroid medullary carcinoma, breast/ovarian cancer and gastric cancer/breast cancer syndrome are encountered in surgery. Some gastric cancer/breast cancer syndrome may be the result of a CDH1 germline mutation. This is the first report of CDH1 germline mutations gastric cancer/breast cancer syndrome in Chinese patients.

METHODS

Peripheral blood from the proband, as well as, her first and second degree relatives was collected and CDH1 gene exon 1-16 mutations were screened. E-cadherin/beta-catenin proteins expression and histopathologic features were examined on gastric cancer/breast cancer tissues from the proband.

RESULTS

A C-->T nucleotide substitution at exon 13 (mRNA 2200 locus, Accession number NM-004360) was found. This was a transition from GCC-->GCT in DNA sequence (Ala154Ala). Diffuse-type gastric cancer and infiltrating ductal breast carcinoma were present. Both tumours preserved E-cadherin/beta-catenin expression immunohistochemically.

CONCLUSIONS

Familial cancer syndrome with diffuse-type gastric cancer/breast cancer proband in Chinese has a propensity of early onset during lifespan. No truncating or splice-site CDH1 mutations had been identified in this family. A silent nucleotide variation in exon 13 of the CDH1 gene may contribute to some forms of cancer susceptibility.

Comparative evaluation of immune response after laparoscopical and open total mesorectal excisions with anal sphincter preservation in patients with rectal cancer

AIM: The study of immune response of open versus laparoscopical total mesorectal excision with anal sphincter preservation in patients with rectal cancer has not been reported yet. The dissected retroperitoneal area that contacts directly with carbon dioxide is extensive in laparoscopic total mesorectal excision with anal sphincter preservation surgery. It is important to clarify whether the immune response of laparoscopic total mesorectal excision with anal sphincter preservation (LTME with ASP) in patients with rectal cancer is suppressed more severely than that of open surgery (OTME with ASP). This study was designed to compare the immune functions after laparoscopic and open total mesorectal excision with anal sphincter preservation for rectal cancer.

METHODS: This study involved 45 patients undergoing laparoscopic (n = 20) and open (n = 25) total mesorectal excisions with anal sphincter preservation for rectal cancer. Serum interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor α (TNF_α) were assayed preoperatively and on days 1 and 5 postoperatively. CD3⁺ and CD56⁺ T lymphocyte count, CD3^- and CD56⁺ natural killer cell (NK) count and immunoglobulin (IgG/IgM/IgA) were assayed preoperatively and on day 5 postoperatively. The numbers of CD3⁺ and CD56⁺ T lymphocytes and CD3^- and CD56⁺ NK cells were counted using flow cytometry. An enzyme-linked immunosorbent assay (ELISA) was used for IL-2, IL-6 and TNF_α determination. And IgG, IgM, and IgA were assayed using immunonephelometry.

RESULTS: The demographic data of the two groups had no difference. The preoperative levels of CD3⁺ and CD56⁺ T lymphocyte count, CD3^- and CD56⁺ NK count, serum IgG, IgM, IgA, IL-2, IL-6 and TNF_α also had no significant difference in the two groups (P > 0.05). The CD3⁺ and CD56⁺ T lymphocyte counts had no obvious changes after surgery in laparoscopic (d = -0.79% ± 3.83%) and open (d = 0.42% ± 2.09%) groups. The CD3^- and CD56⁺ NK counts were decreased postoperatively in both laparoscopic (d = -7.23% ± 11.33%) and open (d = -9.21% ± 13.93%) groups. The differences of the determined values of serum IgG, IgM and IgA on the fifth day after operation subtracted those before operation were -2.56 ± 2.14 g/L, -252.35 ± 392.94 mg/L, -506.15 ± 912.24 mg/L in laparoscopic group, and -1.81 ± 2.10 g/L, -282.72 ± 356.75 mg/L, -252.20 ± 396.28 mg/L in open group, respectively. The levels of IL-2 were decreased after operation in both groups. However, the levels of IL-6 were decreased after laparoscopic surgery (d₁ = -23.14 ± 263.97 ng/L and d₅ = -40.08 ± 272.03 ng/L), and increased after open surgery (d₁ = 27.38 ± 129.14 ng/L and d₅ = 21.67 ± 234.31 ng/L). The TNF_α levels were not elevated after surgery in both groups. There were no significant differences in the numbers of CD3⁺ and CD56⁺ T lymphocytes and CD3^- and CD56⁺ NK cells, the levels of IgG, IgM, IgA, IL-2, IL-6 and TNF_α between the two groups (P > 0.05).

CONCLUSION: There are no differences in immune responses between the patients having laparoscopic total mesorectal excision with anal sphincter preservation and those undergone open surgery for rectal cancer.

Laparoscopic total mesorectal excision of low rectal cancer with preservation of anal sphincter: A report of 82 cases

AIM: To assess the feasibility and efficacy of laparoscopic total mesorectal excision (LTME) of low rectal cancer with preservation of anal sphincter.

METHODS: From June 2001 to June 2003, 82 patients with low rectal cancer underwent laparoscopic total mesorectal excision with preservation of anal sphincter. The lowest edge of tumors was below peritoneal reflection and 1.5-7 cm from the dentate line (1.5-5 cm in 48 cases, 5-7 cm in 34 cases).

RESULTS: LTME with anal sphincter preservation was performed on 82 randomized patients with low rectal cancer, and 100% sphincter preservation rate was achieved. There were 30 patients with laparoscopic low anterior resection (LLAR) at the level of the anastomosis below peritoneal reflection and 2 cm above from the dentate line; 27 patients with laparoscopic ultralow anterior resection (LULAR) at the level of anastomoses 2 cm below from the dentate line; and 25 patients with laparoscopic coloanal anastomoses (LCAA) at the level of the anastomoses at or below the dentate line. No defunctioning ileostomy was created in any case. The mean operating time was 120 min (ranged from 110-220 min), and the mean operative blood loss was 20 mL (ranged from 5-120 mL). Bowel function was restored and diet was resumed on day 1 or 2 after operation. The mean hospital stay was 8 d (ranged from 5-14). Postoperative analgesics were used in 45 patients. After surgery, 2 patients had urinary retention, one had anastomotic leakage, and another 2 patients had local recurrence one year later. No interoperative complication was observed.

CONCLUSION: LTME with preservation of anal sphincter is a feasible, safe and minimally invasive technique with less postoperative pain and rapid recovery, and importantly, it has preserved the function of the sphincter.

Chemiluminescence detection for hybridization assays on the flow-thru chip, a three-dimensional microchannel biochip

Chemiluminescence (CL) detection is seldom used in two-dimensional solid support microarray platforms because adequate sensitivity and spatial resolution is difficult to achieve. The three-dimensional ordered microchannels of the Flow-thru Chip increase both the sensitivity and spatial resolution required for quantitative CL measurements on microarrays. Enzyme-catalyzed CL reactions for the detection of hybridizations on microchannel glass were imaged using a CCD camera. Signal uniformity, sensitivity, and dynamic range of the detection method were determined. The relative standard deviation of signal intensities across an array of 64 spots was 8.1%. A detection limit of 250 amol of target with a linear dynamic range of 3 orders of magnitude was obtained for a 3-h assay. Similar to two-color fluorescence measurements, multiple enzyme labels were employed to demonstrate two-channel chemiluminescence. A unique method for measuring the relaxation time of a chemiluminescent species is also described.

Interactions of HLA-B27 with the peptide loading complex as revealed by heavy chain mutations

MHC class I heavy chains assemble in the endoplasmic reticulum with beta(2)-microglobulin and peptide to form heterotrimers. Although full assembly is required for stable class I molecules to be expressed on the cell surface, class I alleles can differ significantly in their rates of, and dependencies on, full assembly. Furthermore, these differences can account for class I allele-specific disparities in antigen presentation to T cells. Recent studies suggest that class I assembly is assisted by an elaborate complex of proteins in the endoplasmic reticulum, collectively referred to as the peptide loading complex. In this report we take a mutagenesis approach to define how HLA-B27 molecules interact with the peptide loading complex. Our results define subtle differences between how B27 mutants interact with tapasin (TPN) and calreticulin (CRT) in comparison to similar mutations in other mouse and human class I molecules. Furthermore, these disparate interactions seen among class I molecules allow us to propose a spatial model by which all class I molecules interact with TPN and CRT, two molecular chaperones implicated in facilitating the binding of high-affinity peptide ligands.

Tapasin enhances peptide-induced expression of H2-M3 molecules, but is not required for the retention of open conformers

H2-M3 is a class Ib MHC molecule that binds a highly restricted pool of peptides, resulting in its intracellular retention under normal conditions. However, addition of exogenous M3 ligands induces its escape from the endoplasmic reticulum (ER) and, ultimately, its expression at the cell surface. These features of M3 make it a powerful and novel model system to study the potentially interrelated functions of the ER-resident class I chaperone tapasin. The functions ascribed to tapasin include: 1) ER retention of peptide-empty class I molecules, 2) TAP stabilization resulting in increased peptide transport, 3) direct facilitation of peptide binding by class I, and 4) peptide editing. We report in this study that M3 is associated with the peptide-loading complex and that incubation of live cells with M3 ligands dramatically decreased this association. Furthermore, high levels of open conformers of M3 were efficiently retained intracellularly in tapasin-deficient cells, and addition of exogenous M3 ligands resulted in substantial surface induction that was enhanced by coexpression of either membrane-bound or soluble tapasin. Thus, in the case of M3, tapasin directly facilitates intracellular peptide binding, but is not required for intracellular retention of open conformers. As an alternative approach to define unique aspects of M3 biosynthesis, M3 was expressed in human cell lines that lack an M3 ortholog, but support expression of murine class Ia molecules. Unexpectedly, peptide-induced surface expression of M3 was observed in only one of two cell lines. These results demonstrate that M3 expression is dependent on a unique factor compared with class Ia molecules.

Evaluation of three-dimensional microchannel glass biochips for multiplexed nucleic acid fluorescence hybridization assays

Three-dimensional, flow-through microchannel glass substrates have a potential for enhanced performance, including increased sensitivity and dynamic range, over traditional planar substrates used in medium-density microarray platforms. This paper presents a methodology for the implementation of multiplexed nucleic acid hybridization fluorescence assays on microchannel glass substrates. Fluorescence detection was achieved, in a first instance, using conventional low-magnification microscope objective lenses, as imaging optics whose depth-of-field characteristics match the thickness of the microchannel glass chip. The optical properties of microchannel glass were shown, through experimental results and simulations, to be compatible with the quantitative detection of heterogeneous hybridization events taking place along the microchannel sidewalls, with detection limits for oligonucleotide targets in the low-attomole range.

Association of ERp57 with Mouse MHC Class I Molecules Is Tapasin Dependent and Mimics That of Calreticulin and not Calnexin

Before peptide binding in the endoplasmic reticulum, the class I heavy (H) chain-beta(2)-microglobulin complexes are detected in association with TAP and two chaperones, TPN and CRT. Recent studies have shown that the thiol-dependent reductase, ERp57, is also present in this peptide-loading complex. However, it remains controversial whether the association of ERp57 with MHC class I molecules precedes their combined association with the peptide-loading complex or whether ERp57 only associates with class I molecules in the presence of TPN. Resolution of this controversy could help determine the role of ERp57 in class I folding and/or assembly. To define the mouse class I H chain structures involved in interaction with ERp57, we tested chaperone association of L(d) mutations at residues 134 and 227/229 (previously implicated in TAP association), residues 86/88 (which ablate an N-linked glycan), and residue 101 (which disrupts a disulfide bond). The association of ERp57 with each of these mutant H chains showed a complete concordance with CRT, TAP, and TPN but not with calnexin. Furthermore, ERp57 failed to associate with H chain in TPN-deficient.220 cells. These combined data demonstrate that, during the assembly of the peptide-loading complex, the association of ERp57 with mouse class I is TPN dependent and parallels that of CRT and not calnexin.

[Investigation of relationship between concentrated platelets and basic platelets in donors]

OBJECTIVE

To investigate the relationship between the concentrated platelets and basic platelets of donors.

METHODS

We observed the harvest rate of concentrated platelets of different basic platelets in donors from Changsha area and non-Changsha area.

RESULTS

The number of concentrated platelets in Group B was higher than that in Group A (P < 0.01). The harvest rates were 65.4% and 67.5% respectively in donors from Changsha area and non-Changsha area.

CONCLUSION

There is positiver relationship between the harvest rate of concentrated platelets and basic platelets, and the transportation of blood does not effect the harvest rate of platelets.

Kb, Kd, and Ld molecules share common tapasin dependencies as determined using a novel epitope tag

The endoplasmic reticulum protein tapasin is considered to be a class I-dedicated chaperone because it facilitates peptide loading by proposed mechanisms such as peptide editing, endoplasmic reticulum retention of nonpeptide-bound molecules, and/or localizing class I near the peptide source. Nonetheless, the primary functions of tapasin remain controversial as do the relative dependencies of different class I molecules on tapasin for optimal peptide loading and surface expression. Tapasin dependencies have been addressed in previous studies by transfecting different class I alleles into tapasin-deficient LCL721.220 cells and then monitoring surface expression and Ag presentation to T cells. Indeed, by these criteria, class I alleles have disparate tapasin-dependencies. In this study, we report a novel and more direct method of comparing tapasin dependency by monitoring the ratio of folded vs open forms of the different mouse class I heavy chains, L(d), K(d), and K(b). Furthermore, we determine the amount of de novo heavy chain synthesis required to attain comparable expression in the presence vs absence of tapasin. Our findings show that tapasin dramatically improves peptide loading of all three of these mouse molecules.

Definition and transfer of a serological epitope specific for peptide-empty forms of MHC class I

Nascent class I molecules have been hypothesized to undergo a conformational change when they bind peptide based on the observation that most available antibodies only detect peptide-loaded class I. Furthermore recent evidence suggests that this peptide-facilitated conformational change induces the release of class I from association with transporter associated with antigen processing (TAP)/tapasin and other endoplasmic reticulum proteins facilitating class I assembly. To learn more about the structure of peptide-empty class I, we have studied mAb 64-3-7 that is specific for peptide-empty forms of L(d). We show here that mAb 64-3-7 detects a linear stretch of amino acids including principally residues 48Q and 50P. Furthermore, we demonstrate that the 64-3-7 epitope can be transferred to other class I molecules with limited mutagenesis. Interestingly, in the folded class I molecule residues 48 and 50 are on a loop connecting a beta strand (under the bound peptide) with the alpha(1) helix (rising above the ligand binding site). Thus it is attractive to propose that this loop is a hinge region. Importantly, the three-dimensional structure of this loop is strikingly conserved among class I molecules. Thus our findings suggest that all class I molecules undergo a similar conformational change in the loop around residues 48 and 50 when they associate with peptide.

An extensive region of an MHC class I alpha 2 domain loop influences interaction with the assembly complex

Presentation of antigenic peptides to CTLs at the cell surface first requires assembly of MHC class I with peptide and beta 2-microglobulin in the endoplasmic reticulum. This process involves an assembly complex of several proteins, including TAP, tapasin, and calreticulin, all of which associate specifically with the beta 2-microglobulin-assembled, open form of the class I heavy chain. To better comprehend at a molecular level the regulation of class I assembly, we have assessed the influence of multiple individual amino acid substitutions in the MHC class I alpha 2 domain on interaction with TAP, tapasin, and calreticulin. In this report, we present evidence indicating that many residues surrounding position 134 in H-2Ld influence interaction with assembly complex components. Most mutations decreased association, but one (LdK131D) strongly increased it. The Ld mutants, with the exception of LdK131D, exhibited characteristics suggesting suboptimal intracellular peptide loading, similar to the phenotype of Ld expressed in a tapasin-deficient cell line. Notably, K131D was less peptide inducible than wild-type Ld, which is consistent with its unusually strong association with the endoplasmic reticulum assembly complex.

Real-time analysis of immunogen complex reaction kinetics using surface plasmon resonance

Real-time biospecific interactions of immunogens, measured via BIAcore, were used to verify qualitatively a biosensor design which relies on analyte binding competition reactions to open cross-linked receptor channels. The complexes of importance are: (1) cardiac troponin I (TnI) and monoclonal mouse anti-TnI IgG mAb 265, (2) TnI and bispecific antibodies (BsAbs) which on one end recognize TnI while the other end recognizes nicotinic acetylcholine receptors (nAChRs), (3) nAChRs and rat anti-nAChR IgG mAb 148, (4) nAChRs and BsAbs, (5) nAChRs and Fab'148-TnI biopolymers, and (6) mAb 265 and Fab-TnI biopolymers. A commonly used sensor chip, CM5, was employed to immobilize TnI by covalent amine coupling, while bilayer membrane-associated protein, nAChR, was noncovalently sequestered on a HPA sensor chip via hydrophobic adsorption of membrane lipids. The epitopes of membrane-bound nAChRs were still available to immunogens after being immobilized. Kinetic rate constants and affinities of these systems were calculated from BIAcore sensorgrams. The order of magnitude for dissociation rate constants of the BsAb/TnI linker complex and biopolymer/mAb 265 complex is 10(-2) s-1, which provides an opportunity for competitive binding of free analyte in the sensing systems.

Calreticulin and calnexin interact with different protein and glycan determinants during the assembly of MHC class I

Before peptide binding, a variety of endoplasmic reticulum (ER) proteins are associated with class I including calnexin, TAP, calreticulin, and tapasin. Although the selective functions of any one of these ER proteins have been difficult to define, individually or in combination they perform two general chaperone functions for class I. They promote assembly of the class I heterotrimeric molecule (heavy (H) chain, beta2m, and peptide) and they retain incompletely assembled complexes in the ER. In this study, we present evidence that calreticulin clearly differs from calnexin in how it associates with class I. Regarding the structural basis of the association, the oligosaccharide moiety in the alpha1 domain and the amino acid residue at position 227 in the alpha3 domain were both found to be critical for the interaction of class I with calreticulin. Interestingly, calreticulin displayed sensitivity to class I peptide binding even in TAP-deficient human or mouse cells. Thus, calreticulin is clearly more specific than calnexin in the structures and conformation of the class I molecule with which it can interact.

Preparation and characterization of bifunctional biopolymers for receptor-based liposomal immunosensing

In this study, we prepared bifunctional biopolymers for development of a novel liposomal immunosensing element. These biopolymers were produced such that a rat monoclonal antibody fragment Fab' was linked to a cardiac protein Troponin I (TnI) peptide by a cross-linking reagent, o-phenylenedimaleimide (o-PDM) or N-sucinimidyl 3-(2-pyridyldithio)propionate (SPDP). The biopolymer formation yields were approximately 10% for Fab-TnIMal and 30% for Fab-TnISPDP. Molar ratios of Fab' to SPDP or o-PDM and conjugated Fab' to TnI peptide and conjugation pH have considerable effects on the biopolymer yield. Purification of these biopolymers was achieved by employing size-exclusion HPLC. These biopolymers can bind to receptor channels on one end, while the peptide end can be recognized by an anti-TnI antibody serving as a protein linker to block the channels in the immunosensing element. Then reactions may be used where free analyte competes for cross-linker binding sites whereby channels are rendered active. Characterization of purified biopolymers was performed using gel electrophoresis, ELISAs, and a BIAcore instrument. Furthermore, results of real-time biospecific interaction experiments with use of the BIAcore show that competition binding reactions of free TnI peptide occurred in this new immunosensing design. The binding activities of these two biopolymers are slightly different.

WAF1/CIP1 protein expression in human breast tumors

WAF1/CIP1 is a cyclin-dependent kinase inhibitor which is directly induced by p53 and negatively controls cell proliferation. To test the hypothesis that increased levels of WAF1 would be associated with a lower S-phase fraction and better prognosis, WAF1 protein was assessed by immunohistochemistry (IHC) in 115 node-negative human breast tumors, and results were correlated with established prognostic factors and clinical outcome. Nuclear staining was observed in malignant cells in 43% of tumors. In most (90%) of the positive tumors, the proportion of cells staining for WAF1 was low (< 10%). WAF1 was not detected in the cytoplasm, or in non-malignant epithelium. Contrary to expectations, the accumulation of p53 protein, a surrogate marker of p53 inactivation, was weakly but positively associated with WAF1 expression (p = 0.05). Surprisingly, there was no significant correlation with S-phase fraction, ER or PgR status, tumor size, age, ploidy, nuclear grade, or survival.

CONCLUSION

WAF1 expression is found in the nuclei of a small fraction of cells in human breast tumors. WAF1 status is not significantly associated with cell proliferation, other established prognostic factors, or clinical outcome.

Role of murine NK cells and their receptors in hybrid resistance

Hybrid resistance refers to the rejection of parental strain bone marrow cells by natural killer cells of mice that are F1 hybrids derived from two inbred parental strains. This pattern of rejection is not seen in solid organ transplants. Progress in understanding this exception to the laws of transplantation genetics has occurred with the recent discovery of negative signaling receptors for MHC class I molecules. In the last year the discovery of natural killer cell subsets with non-overlapping inhibitory receptors for parental class I molecules has provided an explanation for hybrid resistance. In some instances, however, positive rather than negative signaling seems to be the basis for rejection of allogeneic as well as parental marrow cell grafts.

Allorecognition by murine natural killer cells: lysis of T-lymphoblasts and rejection of bone-marrow grafts

Natural killer (NK) cells of inbred mice reject allogeneic bone-marrow cells, and NK cells of F1 hybrid mice can reject parental bone-marrow cells (hybrid resistance). In some cases these patterns of rejection can be mimicked in vitro by utilizing IL-2 cultured NK effector cells and allogeneic or parental T-lymphoblasts as target cells. Lysis of allogeneic and parental targets in vitro can be explained on the basis of the missing self hypothesis. Subsets of NK cells that bear non-overlapping MHC class I inhibitory receptors belonging to the Ly49 family lyse allogeneic targets because they do not express self class I molecules of the NK cell donor. Parental strain targets are lysed because they do not express all of the self class I antigens of the F1 hybrid, and hence fail to deliver inhibitory signals to all subsets of F1 NK cells. The expression of Ly49 receptors on NK cells is regulated by host MHC to ensure maximal sensitivity to alterations in self class I molecules and to prevent autoreactivity. In many instances, however, the rejection of allogeneic bone marrow cells in vivo cannot be readily explained by the missing self hypothesis. In these instances, it appears that rejection is initiated by class I MHC receptors on NK cells that recognize allogeneic class I molecules as non-self, and activate rather than inhibit NK cell function.

Kinetic modeling and analysis of a vesicle system for immunosensor development

A novel mechanism is presented for immunosensor development that uses an immunological competition reaction in a vesicle system. This system consists of a suspension of reconstituted vesicles, channel agonist, protein linker to block the channels, voltage sensitive dye and analyte to be detected. In the proposed mechanism analyte serves a catalytic role as individual analytes competitively displace multiple channel linkers through association with one channel, dissociation and new associations with other channels. When one channel opens on a vesicle a permanent Nernst potential develops for that vesicle leading to fluorescence of voltage sensitive dyes. The time constant of the redistribution from linker-channel form to analyte-channel form is 0.92/k4 (k4 is the off-rate constant for the analyte-channel association) in the region of analyte concentrations less than 10(-9) M. Kinetic analyses show that several factors, including concentration of analyte or linker, number of channels per vesicle, on-rate or off-rate constant of the linker-channel and on-rate constant of analyte-channel complexes have significant effects on the minimum signal response time.

The role of Ly49A and 5E6(Ly49C) molecules in hybrid resistance mediated by murine natural killer cells against normal T cell blasts

We address the mechanism of hybrid resistance (HR) in vitro using NK effector cells and target lymphoblasts from H-2b, H-2d, and H-2b/d mice. The 5E6 (Ly49C)+ subset of F1 NK cells lyse BALB/c (H-2d) but not B6 (H-2b) targets unless either anti-5E6 or anti-H-2Kb MAbs are present. H-2Dd transgenic B6 (D8) targets are not susceptible to F1 Ly49A+ effectors. Furthermore, 5E6+ Ly49A+ F1 effectors lyse B6 and BALB/c targets only in the presence of anti-5E6 and anti-Ly49A MAbs, respectively. Thus, recognition of H-2Kb by 5E6 and H-2Dd by Ly49A transduce independent inhibitory signals. Moreover, anti-5E6 MAbs enable 5E6+ BALB/c NK cells to lyse (BALB/c x B6)F1 targets. These data support the "missing self" and not the "hemopoietic histocompatibility antigen" hypothesis for HR. In addition, 5E6+ NK cells from BALB/c and BALB.B, but not B6 or (BALB/c x B6)F1, mice receive negative signals from both H-2d and Kb class I antigens. Thus, allelic differences in 5E6 (C57BL versus BALB) may regulate recognition events by NK cells.

Hybrid resistance: 'negative' and 'positive' signaling of murine natural killer cells

Murine NK cells can reject allogenic or parental-strain bone marrow cells (BMC) in vivo and can lyse T lymphoblasts in vitro. The 'missing self' hypothesis states that absence or presence of 'negative signals' from target cell class I antigens (Ag) to NK receptors determines whether or not lysis occurs. Indeed, lysis of parental-strain blasts by purified F1 NK cell subsets occurred only in the presence of anti-receptor antibodies. Evidence for 'positive signaling' to NK cells by class I Ag includes rejection of D8 (Dd) transgene to B6) BMC by B6 hosts. The outcome of other BMC transplants contradict the missing self idea, because donors with identical class I Ag differ in compatibility with certain hosts. Perhaps class I Ag-NK cell receptor interactions dominate over other target-NK cell interactions. These interactions are usually 'negative' but can be 'positive'.

Natural killer cells recognize common antigenic motifs shared by H-2Dd, H-2Ld and possibly H-2Dr molecules expressed on bone marrow cells

Murine natural killer (NK) cells can mediate specific rejection of bone marrow cell (BMC) allografts. Whereas positive recognition of allogeneic MHC antigens forms the basis for T cell alloreactivity, it has been postulated that NK cells are reactive against targets that do not express certain self-encoded MHC class I antigens. Here, we study the immunogenicity of BMC grafts from two class I transgenic mice, D8 (B6 mice with an H-2Dd transgene) and C3H.Ld (C3H mice with an H-2Ld transgene). D8 BMC grafts are acutely rejected by B6 but not D8 recipients. This suggests that antigenic motifs associated with the H-2Dd molecule are recognized. B6 mice depleted of their CD3+ but not NK1.1+ cells can still reject D8 BMC grafts. These data suggest that NK1.1+/CD3- cells recognize the H-2Dd derived antigenic motifs. Similarly, C3H.Ld BMC grafts are rejected by B6 x C3H F1 but not B6 x C3H.Ld F1 recipients. Thus, antigenic motifs associated with the H-2Ld molecule can also be recognized. Furthermore, expression of either H-2Dd or H-2Ld by the recipients renders them unable to reject D8 or C3H.Ld BMC grafts. Therefore, H-2Dd and H-2Ld molecules appear to express common antigenic motifs recognized by NK cells. Additional studies with B6.R4 (KbIbSbDr), an intra-H-2 recombinant mouse, indicated that a third class I molecule, possibly H-2Dr, also shared the common antigenic motifs with both H-2Dd and H-2Ld molecules. Thus, positive recognition of class I antigens by NK cells can occur. However, expression of some of these antigenic motifs appear to be negatively controlled by certain H-2r genes as suggested by rejection of D8 and B6.R4 BMC grafts by D8 x B10.RIII F1 and B6.R4 x B10.RIII F1 hybrids respectively.

p53 protein accumulation detected by five different antibodies: relationship to prognosis and heat shock protein 70 in breast cancer

Nuclear accumulation of p53 protein is associated with a poorer clinical outcome in breast cancer patients. Heat shock protein 70 (hsp70) is a chaperone that binds to mutant p53 and consequently could regulate its accumulation or localization. The aims of this study were to determine if the prognostic significance of p53 accumulation was dependent on the type of antibody used for detection and whether hsp70 was associated with this accumulation. Node-negative breast tumors (n = 169) were examined by immunohistochemistry for nuclear p53, cytoplasmic or nuclear hsp70, and for p53 gene alteration by single-strand conformation polymorphism analysis. Frozen sections of pulverized breast tumors were stained with five p53 antibodies (240, 1801, 421, BP53-12, and CM1), a cocktail of both 240 and 1801, and the hsp70 antibody C92. Protein level was expressed as the sum of a proportion and intensity score (total 0, 2-8) with > or = 2 defined as positive staining. The cocktail 240/1801 gave the highest rate of positive staining (45%), followed by BP53-12 (35%), 1801 (27%), 240 (25%), CM1 (24%), and 421 (18%), with a high correlation between antibodies. Positive staining with each individual antibody or the cocktail was significantly associated with estrogen receptor and progesterone receptor negativity, age < 50, and high S-phase fraction. Only staining detected by the 240/1801 cocktail was associated with significantly worse overall survival; 85 versus 70% at 5 years for p53-negative compared to p53-positive tumors, respectively (P = 0.02). There was no association between nuclear or cytoplasmic hsp70 staining and accumulation of p53. Patients that were p53-negative/cytoplasmic hsp70-positive had a better overall survival than those that were p53-negative/cytoplasmic hsp70-negative. No other combination of p53 and hsp70 status could further define subsets of patients with a significantly different prognosis compared to p53 status alone. Tumors without a detectable p53 gene alteration by single-strand conformation polymorphism but with accumulated p53 protein did not have relatively increased levels of hsp70. We conclude that in node-negative breast cancer, the cocktail of two antibodies, 240/1801, resulted in the highest rate of positive staining and was most strongly associated with overall survival compared with either antibody alone or with the other individual antibodies. By immunohistochemistry, nuclear accumulation of p53 was not associated with cytoplasmic or nuclear hsp70 levels.

Regulatory action of Astragalus saponins and buzhong yiqi compound on synthesis of nicotinic acetylcholine receptor antibody in vitro for myasthenia gravis

With overall analysis of symptoms and signs of myasthenia gravis (MG) basing on "Pi (Spleen) Deficiency" [symbol: see text] theory and with years of our clinical experience in treating MG, we performed a pharmacological study of Astragalus saponins and Buzhong Yiqi Compound (Tonic granulae invigorating vital energy) in 14 peripheral blood mononuclear cell (PBMNC) cultures from 10 MG patients. PBMNG from two groups of patients given dexamethasone (Dxm) and cobalt 60 (60Co) treatment were used as controls. The results showed that water soluble Astragalus saponins significantly reduced the titer of nicotinic acetylcholine receptor antibodies (nAchR-Ab) in the cell culture supernatants, from 418.8-2328 to nil in 6 cases, and from 1143-1235 to 43-157 fmol/ml in 2 cases, and that Buzhong Yiqi compound also had inhibitory immunoregulatory action.

An alpha-fetoprotein-producing carcinoma of the rectum

A rare alpha-fetoprotein (AFP)-producing carcinoma that originated in the rectum of a 54-year-old man is reported. High levels of AFP are found in the serum (5,126 ng/ml) and homogenate of the tumor tissue (2,600 ng/g). Two morphologic patterns were noted in the tumor. One was that of well differentiated tubular adenocarcinoma and the other was more polymorphous, in which the tumor cells grow in a solid-sheet with occasional glandular and papillary structures. Hyaline bodies and Schiller-Duval body-like structures were also found in the polymorphous area. There was a gradual transition between the well differentiated and the polymorphous area. AFP was positive in the polymorphous area and negative in the well differentiated area on immunohistochemical examination. These morphologic and immunohistochemical characteristics may suggest a differentiation toward embryonal carcinoma of the polymorphous component. Moreover, the polymorphous component showed marked vascular invasion and metastasis of liver as well as regional lymph nodes. AFP-producing carcinoma cells may be more aggressive than ordinary adenocarcinoma.

Histochemical detection of lipid peroxidation in human gastrointestinal, mammary and renal carcinomas

Constitutional lipid peroxidation in randomly selected 32 cases of clinically advanced carcinoma from human gastrointestinal tract (20 cases), breast (8 cases) and kidney (4 cases) was examined histochemically in frozen sections using cold Schiff's reagent. Only two cases of gastrointestinal carcinoma were positive by the reagent. Non-cancerous parenchymal cells were negative. These findings suggest that detectable constitutional lipid peroxidation seldom occurs in either cancerous or normal tissues. The capacity for normal and neoplastic tissues to undergo lipid peroxidation was also studied by incubation with an iron-NADPH pro-oxidant system. Normal parenchymal cells showed, to various degrees, a positive reactivity. In gastrointestinal carcinoma, 6 out of 7 cases of well differentiated adenocarcinoma reacted positively, whereas 2 out of 8 cases of moderately to poorly differentiated adenocarcinoma disclosed weakly positive reactions. Mucinous adenocarcinomas (4 cases) were all negative. Signet-ring cell carcinoma (1 case) was positive. One out of 8 cases of breast cancer also showed positive reaction. Four renal cell carcinomas were all negative. Cancer cells have lower capacity to undergo lipid peroxidation than normal cells, when the iron-NADPH pro-oxidant system was employed. In gastrointestinal carcinoma, the ability to undergo lipid peroxidation by the iron-NADPH pro-oxidant seems to be correlated with their histological differentiation. This fact may suggest that differences in lipid composition or the NADPH enzyme system exist between well differentiated and poorly differentiated gastrointestinal malignancies.

Murine natural killer cells and marrow graft rejection

Rejection of bone marrow transplants in lethally irradiated mice differs from rejection of solid tissue grafts in several respects. The genetic laws that govern rejection of solid tissue grafts often fail with hemopoietic grafts. For example, F1 hybrids between two H-2 disparate strains of mice often reject parental bone marrow cells (BMC), and conversely, marrow cells of F1 hybrids (H-2 heterozygous) are usually not rejected by either parent or an unrelated allogeneic recipient. Thus, unlike the classical MHC antigens, the hemopoietic histocompatibility (Hh) antigens relevant in marrow graft rejection are inherited in a recessive pattern. The major Hh (Hh-1) locus maps within the mouse H-2 complex between the H-2S and H-2D regions, and it can therefore be dissociated from the class-I MHC genes. Nevertheless, it is possible that class-I MHC antigens play a role in the formation or expression of Hh-1 antigens. Three models that explain the possible relationship between class-I MHC and Hh-1 genes and the noncodominant pattern of inheritance of Hh antigens are presented. The effector cells responsible for resisting BMC grafts are different from those responsible for rejection of solid tissue grafts. Three cell types, natural killer cells (CD3-, NK1.1+), cytotoxic T cells (CD3+, CD8+), and T cells with natural killer cell markers (CD3+, NK1.1+) have been implicated in the rejection of BMC grafts. Involvement of these cell types is reviewed and the relative roles played by each are discussed. Evidence supporting the existence of Hh-1 specific subsets of NK cells is presented.

An essential replication gene, repA, of plasmid pSC101 is autoregulated

Measurements of the rate of replication of a mutant pSC101 plasmid, cloned into a ColE1 vector, showed that insertions of the transposon Tn1000 into the repA gene of pSC101 abolished replication activity, but could be complemented in trans, albeit at a low level. The promoter of the repA gene was mapped by the construction of repA-lacZ gene fusions, and one of the fusions was used to demonstrate that repA protein, provided in trans, could repress expression of beta-galactosidase activity. This repression was primarily due to reduction of transcription of the repA-lacZ fusion. The sequence analysis of mutants of the repA-lacZ fusion gene which were no longer sensitive to the presence of repA protein showed that the site of action of repA was a 22 base-pair sequence, present as an inverted repeat, overlapping the repA promoter. The repA gene is thus autoregulated.

Genetic analysis of the nitrogen fixation system in Klebsiella pneumoniae

Fine structure mapping of nif mutations of Klebsiella pneumoniae was accomplished by means of Pl-transductional crosses and the plasmid R144 drd mediated conjugations. The physical distance between nif mutations based on the percentage of co-transduction with hisD of the nif mutations was estimated. The maximal distance between two mutations was calculated about 3 Kb, and the average distance between different nif mutations was about 1 to 2 Kb. So no "silent region" was shown within the nif cluster nearby the histidine operon. Several hisD-unlinked nif mutants were isolated and investigated genetically and biochemically. They all differed from the glutamineless mutants, one of these mutants was tentatively assigned as a sort of N-assimilation mutant with little activity of glutamate synthetase. It differed from the known N-assimilation mutants in its absence of nitrogenase activity. Since the wild type hisD-linked nif genes carried by the plasmid RP4 failed to complement the defects of the hisD-unlinked nif genes in the recipient cells but they were effective to facilitate E. coli in acquiring the ability to fix nitrogen, which indicates that the hisD-unlinked nif genes necessary for the functioning of the hisD-linked nif genes are present in E. coli.

An immunocytochemical study of human pituitary mammotropes from fetal life to old age

The objectives were to (a) describe the cytology and distribution of mammotropes in the human pituitary gland, (b) determine whether the mammotrope is a distinctive secretory cell type and (c) ascertain when it first appears in the fetal hypophysis. Identification of mammotropes was based primarily on the Sternberger peroxidase-antiperoxidase immunocytochemical method used with an antiserum to human prolactin. Hypophyses from 25 male and 6 female adults, and 21 fetuses ranging in gestational age from 6 to 23 weeks were studied. In the adult two morphological forms of mammotropes were observed. Mammotrope I possessed a small perikaryon that commonly was located centrally in parenchymal cell cords. From the perikaryon long cytoplasmic processes extended toward neighboring capillaries. Mammotrope I reached its highest incidence in the posterolateral zones of the pars distalis. Mammotrope II possessed a larger perikaryon with short processes; cells of this form were fewer and occurred chiefly in the anteromedian zone. Mammotropes with intermediate morphological features that prevented classification into categories I or II were common in some hypophyses. Both forms of mammotropes were present prepuberally (one 6-week and one 9-year-old male) and in adult males and females. Mammotropes were only slightly more prominent in females than males. Regression of mammotropes was evident in old age. Mammotropes were distinctly different from somatotropes, corticotropes, gonadotropes and thyrotropes. In the fetal hypophysis mammotropes appeared first at 14 weeks of gestational age and remaind few through 16.5 weeks. Their number increased greatly at 23 weeks.

Immunocytochemical analysis of cells in the pars tuberalis of the rat hypophysis with antisera to hormones of the pars distalis

The objective was to acquire evidence regarding the secretory capacity of cells in the pars tuberalis of the rat pituitary by the application of immunocytochemical staining. For this purpose the conjugated antibody and immunoglobulin-enzyme bridge techniques were utilized with antisera to the following hormones of the pars distalis: human somatotropin, human thyrotropin, human beta-melanotropin, ovine luteinizing hormone (LH), porcine beta17-39-corticotropin, and beta1-24-corticotropin. Only LH-containing cells were demonstrated. They were exceedingly rare in the cephalic pars tuberalis beneath the median eminence. The frequency of LH-cells was greater in the pars tuberalis associated with the infundibulum and increased distally. LH-cells were most common ventrolateral to the infundibular stem and occurred singly and in clusters. These results indicate that following hypophysectomy the portion of the pars tuberalis that remains in situ has the capacity to secrete only LH of all the pars distalis hormones.