Biomedical subjects

Hao Li

Publications and source records attributed to Hao Li.

At least 91 records · Page 5Linked to original sources

PubMed2005

[Molecular biological survey of tick-born arboviruses in southern part of Xinjiang].

BACKGROUND: To disclose the species and distribution of tick-borne arboviruses in the southern part of Xinjiang. METHOD: Totally 5045 ticks were collected from 36 collecting sites of 23 places in the southern Xinjiang, which were made into cDNA pools with pd(N)6 primer through RT-PCR method. Then PCR was used to detect viral nucleotide sequence from cDNA. RESULTS: All 34 cDNAs showed negative to flavivirus and California serogroup virus primers; but nairovirus and primers derived from Xinjiang hemorrhagic fever virus had amplified and yielded some obvious bands corresponding to the nucleotide sequences of Xinjiang hemorrhagic fever virus. A phylogenetic analysis was done to the obtained partial sequences of L and S segments. CONCLUSION: Nucleotide sequences of Neither flaviviruses nor California serogroup viruses were detected from the samples. However partial L segment sequence was first reported in China. Phylogenetic analysis of partial L and S segments disclosed the molecular characteristic of Xinjiang hemorrhagic fever virus.

Animals↗

PubMed2005

[Establishment of a modified larynx transplantation model with inbred F344 rat].

BACKGROUND & OBJECTIVE: As a non-vital organ, transplantation of larynx lags behind that of the other organs, but it is supposed that if induction of immunologic tolerance of the host to the allograft comes true, larynx transplantation would be an optimal approach for management of advanced laryngeal cancer as well as functional reconstruction of the larynx. This study was designed to establish a modified rat model of larynx transplantation to improve survival rate of the recipients and vitality of the allografts, and provide an optimal rat model for further research on immunology and induction of immunologic tolerance in larynx transplantation. METHODS: A Strome's model of larynx transplantation was repeated with inbred F344 rats (40 rats in Stroma model A and 40 rats in Stroma model B). A modified model of larynx transplantation was developed (40 rats), in which both superior thyroid arteries and ascending pharyngeal arteries were preserved, combining with the hyoid, base of the tongue, hypopharynx, larynx, thyroid, part of the cervical trachea and cervical esophagus as an allograft complexity. The blood supply of the allograft was reconstructed through end-to-end anastomosis of the donors' carotid arteries with the recipients' carotid artery and anterior jugular vein. The recipients were injected with 15 ml of 5% glucose normal saline (GNS) through contralateral external jugular vein intraoperatively, and injected subcutaneously with 5 ml of 5% GNS daily for 3-5 days postoperatively. Morphology of the allografts and patency of the arteries and veins were observed under microscope 7 days after operation, and vitality of the allogafts was assessed pathologically. Survival of the recipients and vitality of the allografts in Strome model and modified model were compared. RESULTS: Survival rates of the recipient rats were 70% in Strome model A, 85% in Strome model B, and 95% in modified model; the survival rates of the allografts were 30% in Strome model A, 40% in Strome model B, and 80% in modified model, respectively. CONCLUSIONS: Compare with Strome models, the modified model of larynx transplantation reduces mortality of the recipients through enhancing perioperative care, improves vitality of the allografts through including both ascending pharyngeal arteries and superior thyroid arteries in the allograft complexity, which increases blood supply of the allografts and reduces micro-circulation resistance, therefore, reduces the micro-circulation malfunction of the allografts.

Anastomosis, Surgical↗

PubMed2004

Analysis of oligonucleotide array experiments with repeated measures using mixed models.

BACKGROUND: Two or more factor mixed factorial experiments are becoming increasingly common in microarray data analysis. In this case study, the two factors are presence (Patients with Alzheimer's disease) or absence (Control) of the disease, and brain regions including olfactory bulb (OB) or cerebellum (CER). In the design considered in this manuscript, OB and CER are repeated measurements from the same subject and, hence, are correlated. It is critical to identify sources of variability in the analysis of oligonucleotide array experiments with repeated measures and correlations among data points have to be considered. In addition, multiple testing problems are more complicated in experiments with multi-level treatments or treatment combinations. RESULTS: In this study we adopted a linear mixed model to analyze oligonucleotide array experiments with repeated measures. We first construct a generalized F test to select differentially expressed genes. The Benjamini and Hochberg (BH) procedure of controlling false discovery rate (FDR) at 5% was applied to the P values of the generalized F test. For those genes with significant generalized F test, we then categorize them based on whether the interaction terms were significant or not at the alpha-level (alphanew = 0.0033) determined by the FDR procedure. Since simple effects may be examined for the genes with significant interaction effect, we adopt the protected Fisher's least significant difference test (LSD) procedure at the level of alphanew to control the family-wise error rate (FWER) for each gene examined. CONCLUSIONS: A linear mixed model is appropriate for analysis of oligonucleotide array experiments with repeated measures. We constructed a generalized F test to select differentially expressed genes, and then applied a specific sequence of tests to identify factorial effects. This sequence of tests applied was designed to control for gene based FWER.

Algorithms↗

PubMed2004

Apolipoprotein A-I induces translocation of protein kinase C[alpha] to a cytosolic lipid-protein particle in astrocytes.

Apolipoprotein A-I (apoA-I) induces the translocation of newly synthesized cholesterol as well as caveolin-1 to the cytosolic lipid-protein particle (CLPP) fraction in astrocytes before its appearance in high density lipoprotein generated in the medium (Ito, J., Y. Nagayasu, K. Kato, R. Sato, and S. Yokoyama. 2002. Apolipoprotein A-I induces translocation of cholesterol, phospholipid, and caveolin-1 to cytosol in rat astrocytes. J. Biol. Chem. 277: 7929-7935). We here report the association of signal-related molecules with CLPP. ApoA-I induces rapid translocation of protein kinase Calpha to the CLPP fraction and its phosphorylation in astrocytes. ApoA-I also induces the translocation of phospholipase Cgamma to CLPP. Diacylglyceride (DG) production is increased by apoA-I in the cells, with a maximum at 5 min after the stimulation, and the increase takes place also in the CLPP fraction. An inhibitor of receptor-coupled phospholipase C, U73122, inhibited all the apoA-I-induced events, such as DG production, cholesterol translocation to the cytosol, release of cholesterol, and translocation of protein kinase Calpha into the CLPP fraction. CLPP may thus be involved in the apoA-I-initiated signal transduction in astrocytes that is related to intracellular cholesterol trafficking for the generation of high density lipoprotein in the brain.

Animals↗

PubMed2004

Gcn4p and novel upstream activating sequences regulate targets of the unfolded protein response.

Eukaryotic cells respond to accumulation of unfolded proteins in the endoplasmic reticulum (ER) by activating the unfolded protein response (UPR), a signal transduction pathway that communicates between the ER and the nucleus. In yeast, a large set of UPR target genes has been experimentally determined, but the previously characterized unfolded protein response element (UPRE), an upstream activating sequence (UAS) found in the promoter of the UPR target gene KAR2, cannot account for the transcriptional regulation of most genes in this set. To address this puzzle, we analyzed the promoters of UPR target genes computationally, identifying as candidate UASs short sequences that are statistically overrepresented. We tested the most promising of these candidate UASs for biological activity, and identified two novel UPREs, which are necessary and sufficient for UPR activation of promoters. A genetic screen for activators of the novel motifs revealed that the transcription factor Gcn4p plays an essential and previously unrecognized role in the UPR: Gcn4p and its activator Gcn2p are required for induction of a majority of UPR target genes during ER stress. Both Hac1p and Gcn4p bind target gene promoters to stimulate transcriptional induction. Regulation of Gcn4p levels in response to changing physiological conditions may function as an additional means to modulate the UPR. The discovery of a role for Gcn4p in the yeast UPR reveals an additional level of complexity and demonstrates a surprising conservation of the signaling circuit between yeast and metazoan cells.

Amino Acid Motifs↗

PubMed2004

A simple and efficient L-prolinamide-catalyzed alpha-selenenylation reaction of aldehydes.

An efficient and simple l-prolinamide-catalyzed alpha-selenenylation reaction of aldehydes with N-(phenylseleno)phthalimide has been developed for the efficient preparation of alpha-phenylselenoaldehydes. Such compounds are versatile building blocks for the synthesis of alpha,beta-unsaturated aldehydes, allylic alcohols, and amines. [reaction: see text]

Journal Article↗

PubMed2004

Protein kinase C-dependent activation of P44/42 mitogen-activated protein kinase and heat shock protein 70 in signal transduction during hepatocyte ischemic preconditioning.

AIM: To investigate the significance of protein kinase C(PKC), P44/42 mitogen-activated protein kinase (MAPKs) and heat shock protein (HSP)70 signal transduction during hepatocyte ischemic preconditioning. METHODS: In this study we used an in vitro ischemic preconditioning (IP) model for hepatocytes and an in vivo model for rat liver to investigate the significance of protein kinase C (PKC), P44/42 mitogen-activated protein kinase (P44/42 MAPKs) and heat shock protein 70 (HSP70) signal transduction in IP. Through a normal liver cell hypoxic preconditioning (HP) model in which cultured normal liver cells were subjected to 3 cycles of 5 min of incubation under hypoxic conditions followed by 5 min of reoxygenation and subsequently exposed to hypoxia and reoxygenation for 6 h and 9 h respectively. PKC inhibitor, activator and MEK inhibitor were utilized to analyze the phosphorylation of PKC, the expression of P44/42 MAPKs and HSP70. Viability and cellular ultrastructure were also observed. By using rat liver as an in vivo model of liver preconditioning (3 cycles of 10-min occlusion and 10-min reperfusion), in vivo phosphorylation of PKC and P44/42MAPKs, HSP70 expression were further analyzed. AST/ALT concentration, cellular structure and ultrastructure were also observed. All the data were statistically analyzed. RESULTS: Similar results were obtained in both in vivo and in vitro IP models. Compared with the control without IP (or HP), the phosphorylation of PKC and P44/42 MAPKs and the expression of HSP70 were obviously increased in IP (or HP) treated model in which cytoprotection could be found. The effects of preconditioning were mimicked by stimulating PKC with 4beta phorobol-12-myristate13-acetate (PMA). Conversely, inhibiting PKC with chelerythrine abolished the protection given by preconditioning. PD98059, inhibitor of MEK (the upstream kinase of P44/42MAPKs), also reverted the cytoprotection exerted by preconditioning. CONCLUSION: The results demonstrate that preconditioning induces a rapid activation of P44/42MAPKs and PKC activation plays a pivotal role in the activation of P44/42 MAPKs pathway that participates in the preservation of liver cells. HSP expression is regulated by signals in PKC dependent P44/42 MAPKs pathway.

Animals↗

PubMed2004

Functional bias and spatial organization of genes in mutational hot and cold regions in the human genome.

The neutral mutation rate is known to vary widely along human chromosomes, leading to mutational hot and cold regions. We provide evidence that categories of functionally related genes reside preferentially in mutationally hot or cold regions, the size of which we have measured. Genes in hot regions are biased toward extracellular communication (surface receptors, cell adhesion, immune response, etc.), while those in cold regions are biased toward essential cellular processes (gene regulation, RNA processing, protein modification, etc.). From a selective perspective, this organization of genes could minimize the mutational load on genes that need to be conserved and allow fast evolution for genes that must frequently adapt. We also analyze the effect of gene duplication and chromosomal recombination, which contribute significantly to these biases for certain categories of hot genes. Overall, our results show that genes are located nonrandomly with respect to hot and cold regions, offering the possibility that selection acts at the level of gene location in the human genome.

Chromosome Mapping↗

PubMed2004

Comparing genomic expression patterns across species identifies shared transcriptional profile in aging.

We developed a method for systematically comparing gene expression patterns across organisms using genome-wide comparative analysis of DNA microarray experiments. We identified analogous gene expression programs comprising shared patterns of regulation across orthologous genes. Biological features of these patterns could be identified as highly conserved subpatterns that correspond to Gene Ontology categories. Here, we demonstrate these methods by analyzing a specific biological process, aging, and show that similar analysis can be applied to a range of biological processes. We found that two highly diverged animals, the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster, implement a shared adult-onset expression program of genes involved in mitochondrial metabolism, DNA repair, catabolism, peptidolysis and cellular transport. Most of these changes were implemented early in adulthood. Using this approach to search databases of gene expression data, we found conserved transcriptional signatures in larval development, embryogenesis, gametogenesis and mRNA degradation.

Age Factors↗

PubMed2004

Potential diagnostic value of pancreatic isoamylases for pancreaticobiliary maljunction with mild biliary dilatation in patients and a porcine model.

PURPOSE: The aim of this study was to evaluate the diagnostic value of serum pancreatic isoamylases for pancreaticobiliary maljunction (PBM) with mild biliary dilatation. METHODS: Serum and bile from 8 children with PBM and mild biliary dilatation (6 to 11 mm in diameter) and 4 young pigs with an anastomosis constructed between an isolated pancreas-duodenal segment and the gallbladder were studied for pancreatic isoamylases. Using an electrophoretic technique, the assay of pancreatic isoamylases was expressed by peak appearance rate (PAR). Serum from 20 healthy children served as normal controls. RESULTS: In the serum of the patients, preoperatively there were 5 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 100%; P4, 100%; and P5, 66.7%. These abnormal pancreatic isoamylases disappeared 2 weeks after operative treatment. In normal controls, there were only P1 (PAR, 40%) and P2 (PAR, 100%). Mild cylindrical dilatation (6 to 8 mm in diameter) of the common bile duct developed in the porcine PBM model. There were P1 (PAR, 100%) and P2 (PAR, 100%) in the porcine serum preoperatively. Thirty days and 60 days after establishing the model, there appeared in the serum 6 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 75%; P4, 100%; P5, 100%, and P6; 75%. The bile patterns of pancreatic isoenzymes in the patients and pigs were similar to those in serum. CONCLUSIONS: Abnormal pancreatic isoamylases are characteristically present in the serum from both children and a porcine model of PBM and mild biliary dilatation. Assay for these abnormalities is promising to recognize this subset of patients in whom diagnosis remains a challenge.

Amylases↗

PubMed2004

An intervention study to prevent gastric cancer by micro-selenium and large dose of allitridum.

BACKGROUND: People have more and more concerned about allitridum as studies have shown that taking more raw garlic associated with a lower risk for cancers of the alimentary system. In the present study, we tried to examine whether a large dose of allitridum and a microdose of selenium prevent gastric cancer. METHODS: A double-blind intervention study was performed on the participants aged (35 - 74) years, who had matched at least one of the following criteria: (1) a medical history of stomach disorder, (2) a family history of tumour, or (3) smoking and/or alcohol consumption. A total of 2,526 and 2,507 persons were randomly enrolled into intervention group and control group respectively from 288 natural villages of seven communities in Qixia County, Shandong Province, China. Each person of the intervention group orally took 200 mg synthetic allitridum every day and 100 microg selenium every other day for one month of each year during November 1989 to December 1991. At the same time, people in control group were given 2 placebo capsules containing corn oid with the identical appearance to that in the intervention group. RESULTS: For all subjects the large dose of allitridum was accepted and no harmful side effects were found during the study. In the first follow-up five years (1992 - 1997) after stopping the intervention, the morbidity rates of malignant tumours in the intervention group declined by 22%, in contrast to the control group, declined by 47.3%. After adjusting for age, gender, and other potential confounders, relative risks (RRs) for all tumours and gastric cancer of the whole population were 0.67 (95% CL: 0.43 - 1.03) and 0.48 (95% CL: 0.21 - 1.06), respectively, and for male group they were 0.51 (95% CL: 0.30 - 0.85) and 0.36 (95% CL: 0.14 - 0.92), respectively. No signigicantly protective effect was found for the female subgroup. CONCLUSION: The present study proves that large doses of allitridum and microdorse of selenium may effectively prevent gastric cancer, especially in men.

Adult↗

PubMed2004

[Effect of huannao yicong capsule on senile mild cognitive impairment].

OBJECTIVE: To observe the effect of Huannao Yicong capsule (HYC) on senile mild cognitive impairment. METHODS: Sixty-two patients were randomly divided into two groups, the 31 patients in the treated group were treated with HYC 3 capsules, 3 times daily, and the 31 in the control group with Hydergin 3 tablets, 3 times daily. Treatment for two successive months was a therapeutic course. The changes of cognitive effect index (CEI), integral of measuring scale (CCSE, FQA and MMSE), TCM Syndrome scoring, quality of life (QOL), cerebral arterial blood flow (CBF) and hemorrheologic parameters in the two groups were observed. RESULTS: The total effective rate of treatment in improving cognition in the 30 patients of the treated group (with one case lost) was 83.33%, while that in the 29 patients of the control group (with two cases lost) was 48.28%, the difference between them was significant (u = 2.36, P < 0.05). Intent-to-treat analysis, namely, the case lost in the treated marked as ineffective and those in the control group as effective, showed the total effective rate in the two groups was 80.65% and 51.61% respectively, which also showed significant difference (u = 2.02, P < 0.05). In the treated group after treatment, the integrals of CCSE, FAQ and MMSE significantly increased (P < 0.05 or P < 0.01), the TCM Syndrome scoring decreased (P < 0.01), the scoring of QOL significantly improved, the mean BBF increased (P < 0.05 or P < 0.01), and the cerebral arterial resistance index improved significantly. All these improvements in the treated group were significantly higher than those in the control group respectively (P < 0.05). Besides, the hemorrheologic parameters in the treated group were improved, most of them were better than those in the control group (P < 0.05 or P < 0.01). CONCLUSION: HYC has good therapeutic effect on senile mild cognitive impairment, it is safe without any adverse reaction.

Aged↗

PubMed2004

[Effect of compound Salvia injection on blood coagulation in patients with traumatic cerebral infarction].

OBJECTIVE: To investigate the effect of compound Salvia injection (CSI) on blood coagulatory function in patients with traumatic cerebral infarction (TCI). METHODS: Sixty-four patients with TCI were randomly divided into two groups, 32 in each group. The treated group were treated with CSI plus conventional treatment of western medicine, and the control group treated with conventional treatment alone. Changes of symptoms, levels of plasma P-selectin (P-S), von Willebrand's factor (vWf) and D-dimer were observed with ELISA. RESULTS: The treated group was superior to the control group in Glasgow outcome scale (P < 0.01). Before treatment, the levels of plasma P-S, vWf and D-dimer in the TCI patients were higher than those in healthy people. After treatment, all the parameters lowered in both groups, but the effect of lowering was greater in the treated group than that in the control group. CONCLUSION: Blood coagulation disorder exists in patients with TCI, CSI could improve it, and might alleviate the cerebral damage to a certain extent.

Blood Coagulation↗

PubMed2004

[Surgical treatment of well-differentiated thyroid carcinoma invading trachea: a report of 15 cases].

BACKGROUND & OBJECTIVES: At present head and neck surgeons from many countries have different opinions on management of well-differentiated thyroid cancer (WDTC). We will discuss WDTC invading trachea surgical treatment and its clinical significance. METHODS: Retrospectively reviewed clinical data of 15 cases WDTC invading trachea, According to WDTC invading extent and grade, there were 3 kinds of surgical approaches: 1) end to end anastomosis; 2) tissue flap reconstruction; 3)larynx-tracheal dissociation. RESULTS: 15 cases underwent radical resection and reconstruct the defect of tracheal or larynx-tracheal dissociation. 2 cases received directly suture, 5 cases received sternocleidomastoid muscle flap reconstruction, 2 cases received pectorlis major muscle flap reconstruction, 2 cases received platysma flap reconstruction, 2 cases received free forearm flap with muticore titanium-board reconstruction, 2 cases received larynx-tracheal dissociation with larynx block out and tracheal fistula. 10 cases (10/15, 66.7%) received decannulation postoperation. Patients who were success fully decannulated could recover phonation and maintain airway breath. In the 5 patients who couldn't decannulate, underwent sternocleidomastoid muscle flap reconstruction, 1 underwent free forearm flap with muticore titanium-board reconstruction, 1 underwent pectorlis major muscle flap reconstruction, 2 underwent larynx-tracheal dissociation, but all of them could hardly utter voice by compress tracheostoma and needed permanent tracheostoma due to collapse of trachea. The recurrence rate of our group is 33.33%, 5 years survival rate is 88.89%. CONCLUSIONS: WDTC with trachea invading easily cause dyspnea or emptysis influencing on 5 years survival rate. We should take more actively surgical approach to resect all the tumor and involved organ, thus improve survival rate and reduce recurrence postoperation.

Adenocarcinoma, Follicular↗

PubMed2003

Genes that act downstream of DAF-16 to influence the lifespan of Caenorhabditis elegans.

Ageing is a fundamental, unsolved mystery in biology. DAF-16, a FOXO-family transcription factor, influences the rate of ageing of Caenorhabditis elegans in response to insulin/insulin-like growth factor 1 (IGF-I) signalling. Using DNA microarray analysis, we have found that DAF-16 affects expression of a set of genes during early adulthood, the time at which this pathway is known to control ageing. Here we find that many of these genes influence the ageing process. The insulin/IGF-I pathway functions cell non-autonomously to regulate lifespan, and our findings suggest that it signals other cells, at least in part, by feedback regulation of an insulin/IGF-I homologue. Furthermore, our findings suggest that the insulin/IGF-I pathway ultimately exerts its effect on lifespan by upregulating a wide variety of genes, including cellular stress-response, antimicrobial and metabolic genes, and by downregulating specific life-shortening genes.

Aging↗

PubMed2003

The effects of serotonin and ecdysone on primary sensory neurons in crayfish.

The overall behaviors and motivational states observed during social interactions and throughout the molting cycle of crayfish have been linked to the effects of humoral neuromodulators. Both serotonin (5-HT) and a molt-related hormone, 20-hydroxyecdysone (20-HE), are known to be present in the hemolymph of crustaceans. To determine if they alter the activity of a primary sensory neuron that monitors proprioceptive information, we examined their effects on the activity of the slow-adapting muscle receptor organ (MRO) of the crayfish abdomen, a model sensory system that has been extensively studied. 5-HT within the range of 100 nM to 1 microM, increases the firing frequency of the neuron during sustained stimulation. In experiments in which 20-HE was added alone, an increase in the firing frequency also occurred, although to a lesser degree than that for 5-HT at the same concentrations. When the MRO is first exposed to 20-HE, followed sequentially by 5-HT, the activity increases to about the same degree as in the reverse order of exposure. This outcome indicates that mixtures of these endogenous neuromodulators, at various levels, are more important in alternating behavior than the absolute level of any one of them introduced alone.

Animals↗

PubMed2003

Dissecting the transcription networks of a cell using computational genomics.

A great challenge in understanding biological complexity in the post-genome era is to reconstruct the regulatory networks governing the patterns of gene expression. In the past few years, the rapid accumulation of genomic sequence and functional data has led to the development of computational approaches to systematically dissect transcriptional regulatory networks. Effective algorithms have been developed to predict cis-regulatory elements in a genome, to identify the target genes of transcription factors, to infer the conditions under which each transcription factor is either activated or deactivated, and to analyze combinatorial regulation by multiple transcription factors. Genomic approaches have profoundly changed the way biologists investigate transcriptional regulation, and global pictures of the transcription networks for several model organisms are beginning to emerge.

Algorithms↗

PubMed2003

Matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase expression in human preimplantation embryos.

OBJECTIVE: To examine human embryos at various stages of preimplantation development for simultaneous expression of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs). DESIGN: mRNAs of specific MMPs and TIMPs were examined in single human embryos, at different stages of preimplantation development, by reverse transcription-polymerase chain reaction (RT-PCR). Single embryo immunohistochemistry was applied to examine the protein expression. SETTING: University-affiliated IVF-ET program. PATIENT(S): Couples, attending the university-affiliated IVF-ET program, electing to donate poor prognosis embryos with anomalous morphology. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The expression of MMP-1, MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 in preimplantation embryos. RESULT(S): The MMP-2 mRNA was expressed consistently during development from one-cell to blastocyst stage. The TIMP-1 and TIMP-3 mRNAs were detected in embryos at all stages; however, in the later preimplantation developmental stages, an increasing proportion of embryos expressing TIMP-1 and TIMP-3 mRNA were noted. The MMP-1, MMP-9, and TIMP-2 mRNAs were detected in only a minority of human embryos studied. Immunohistochemistry showed MMP-1 and TIMP-1 protein expression in preimplantation embryos. CONCLUSION(S): The existence of MMP and TIMP mRNA expression in human preimplantation embryos argues for a role for these metalloproteinases and their inhibitors during the process of implantation in humans.

Blastocyst↗