Determination of HLA class II alleles by genotyping in a Manchu population in the northern part of China and its relationship with Han and Japanese populations

The genetic polymorphism of the HLA class II loci was investigated in a Manchu population resident in the northern part of China and compared with those of other Asian populations including Japanese and Han. In 8 DQA1 alleles, the most frequent allele was DQA1*03 with the gene frequency of 25.5%. Of 15 DQB1 alleles tested, 11 were observed and the most common allele was DQB1*0301 with the gene frequency of 24.5%. Among 19 DPB1 alleles, 11 were detected and DPB1*0501 (43.8%) was the most frequent allele as observed in other Asian populations such as Japanese, Chinese and Korean. Of 43 DRB1 alleles tested, 21 were detected and DRB1*0901 (14.0%), *1501 (11.0%), *1201 (11.0%), *07 (9.0%) and *1401 (9.0%) were highly predominant and account for the high frequencies of DR9, DR2, DR5, DR7 and DR6. In the DRB3 gene (DR52), DRB3*0202 (18.0%) was the most frequent. With respect to the DRB4 gene (DR53), the gene frequency of DRB4*0101 was 35.0%. Of 3 DRB5 alleles detected, DRB5*0101 (11.0%) was highly predominant. Comparison of HLA class II allele frequencies in Manchu with those in Japanese and Han Chinese populations (South & North) detected some significant differences and genetic divergence between these Oriental populations. The dendrogram constructed by the neighbor-joining (NJ) method based on the allele frequencies of DQA1, DQB1, DPB1 and DRB1 of 10 representative populations over the world suggested that Manchu is the closest, but at the same genetic distance to both Northern and Southern Han Chinese.

Idiotypic DNA vaccines against B-cell lymphoma

Idiotypic antigens are clearly defined tumor-associated protein antigens, which can induce protective immunity against lymphoma. Because each patient requires an individual vaccine, idiotypic antigens also provide ideal candidates for exploring the feasibility of replacing protein antigens by DNA vaccines. Component idiotypic variable region genes can be identified in patients' tumor biopsies and rapidly assembled as scFv sequences. These can be used to produce recombinant scFv protein in bacteria, or as direct naked DNA vaccines. A preliminary small trial of DNA vaccines for chemotherapy-resistant patients with lymphoma has begun. Intramuscular idiotypic DNA vaccination in a mouse model induces low levels of anti-idiotypic antibody in serum. Levels can be increased dramatically by coinjection of DNA plasmids encoding either IL-2 or GM-CSF, and specific proliferative anti-idiotypic T cells are induced. However protective immunity remains to be demonstrated, and a possible reason for this may lie in the continued secretion of idiotypic scFv antigen which blocks antibody activity by formation of immune complexes. Methods for regulating secretion of antigen are required before this category of tumor antigen can be fully exploited as a vaccine. The power of DNA technology should allow analysis and manipulation of pathways of antigen presentation to induce maximal therapeutic attack on neoplastic B cells. In addition, lymphoma presents a model for application of DNA technology to the wide range of human tumors known to harbor potential tumor antigens.

Human macrophage colony stimulating factor (HM-CSF) expressed in baculovirus infected insect cells is biologically active in its monomeric form

hM-CSF was reported to have biological activity only in a dimeric form. Using oligonucleotide-directed mutagenesis of hM-CSF (1-149aa) cDNA, we have substituted Ser31 for Cys31 which forms intermolecular disulfide bond in native hM-CSF. The mutant hM-CSF cDNA was expressed in insect BmN cells using baculovirus as a vector under the control of polyhedrin promoter. Biological activity analysis and radioligand receptor assay both showed that there was little difference between the mutant hM-CSF and the native dimeric hM-CSF. These results strongly support that the biologically active human M-CSF in its monomeric form can be expressed in recombinant baculovirus infected insect cells.

[Serum lipid-associated sialic acid (LSA) in diagnosing and monitoring ovarian cancer]

Serum from 161 patients with ovarian cancer, 28 patients with benign gynecologic disorders and 22 healthy women, was assayed for levels of tumor marker LSA, which were compared with CA125. The results showed that in the patients with ovarian cancer, the sensitivities of LSA and CA125 for the patients prior to surgery were 83.0% and 92.5%, respectively; the sensitivities for the recurrent patients after surgery were 73.7% and 82.5% respectively. A total sensitivity of 89.5% was obtained by combination of both markers. The positive predictive value of LSA and CA125 for the patients with suspected tumor recurrence were 89.4% and 100%, respectively, and their corroborative rate with the postoperative courses were 94.4% and 100%, respectively. Thus serum assay of LSA, can be used in monitoring patients with ovarian cancer. The technique for determination of serum level of LSA is much more simple and less expensive than the radioimmuno-assay of serum level of CA125.

Cardiac malformation in neonatal mice lacking connexin43

Gap junctions are made up of connexin proteins, which comprise a multigene family in mammals. Targeted mutagenesis of connexin43 (Cx43), one of the most prevalent connexin proteins, showed that its absence was compatible with survival of mouse embryos to term, even though mutant cell lines showed reduced dye coupling in vitro. However, mutant embryos died at birth, as a result of a failure in pulmonary gas exchange caused by a swelling and blockage of the right ventricular outflow tract from the heart. This finding suggests that Cx43 plays an essential role in heart development but that there is functional compensation among connexins in other parts of the developing fetus.

Splenic lymphoma with villous lymphocytes involves B cells with extensively mutated Ig heavy chain variable region genes

Splenic lymphoma with villous lymphocytes (SLVL) is a recently defined subgroup of chronic B-cell lymphoproliferative diseases. The characteristic morphology of the tumor cells, together with phenotypic and cytogenetic findings, indicate that it is a distinct entity, but the nature of the cell or origin and its relationship to other low-grade lymphomas is unclear. For B-cell tumors, analysis of the variable region heavy chain (VH) genes used to encode the clonal Ig has shown marked differences between histologic categories, both in gene usage and extent of somatic mutation. An investigation of VH genes used in five typical cases of SLVL has shown somatic hypermutation from germline sequences in all cases, indicating that the cell of origin has been exposed to the hypermutation mechanism. However, no clonal heterogeneity was detectable, demonstrating that the tumor cell does not accumulate further mutations. These characteristics are similar to those found in mature postfollicular B cells, such as plasma cells. The distribution of mutations leading to replacement amino acids differed among the cases, with three of five cases showing clear evidence for antigen selection.

Centromere spreading and centromeric aberrations in ovarian tumors

Centromere spreading (CS) of chromosomes and high occurrence of aberrations at centromeric region were observed in two papillary serous cystadenocarcinomas and one borderline papillary serous cystadenoma of the ovary. In the borderline tumor, CS of chromosome 12, trisomy of which had been reported as the sole abnomaly in benign ovarian tumors, was seen in three metaphases. It is suggested that CS may be an early event in the carcinogenesis of epithelial ovarian tumors. Centromeres of some chromosomes in tumor cells may be unstable and thus bring about premature centromere separations and breakages at centromeric regions, followed by some numerical and structural chromosomal aberrations.

Interaction of silkworm larvae expressed monomeric hM-CSF with its receptor on murine bone marrow derived macrophage

Human macrophage colony-stimulating factor (hM-CSF) expressed in the silkworm larvae was monomeric. The nature of the interaction of iodinated monomeric M-CSF with murine bone marrow derived macrophage (BMM) was studied. On incubation with 2 nM [125I]M-CSF at 4 degrees C, approximately 90% of the maximal binding occurred within 15 min with a plateau around 1hr which then gradually declined. Scatchard plot analysis showed that the Kd for the monomeric M-CSF is 5.3 x 10(-10) M and the number of binding sites per cell is 4 x 10(4). Competition experiment indicated that cellular binding of the iodinated monomeric rhM-CSF was almost as effective as the native M-CSF. The results show that the interchain disulfide bond of M-CSF is not essential for the natural folding of active M-CSF.

Yeast-prepro-alpha-factor-leader-region-directed synthesis and secretion of truncated human macrophage colony-stimulating factor in the silkworm Bombyx mori

Human macrophage colony-stimulating factor (hM-CSF) cDNA joined to the leader region of the precursor of the yeast mating pheromone alpha-factor (MF alpha L) was expressed at high levels in BmN cells and in silkworm (Bombyx mori) larvae, using recombinant Bombyx mori nuclear polyhedrosis virus, as a vector. The biological activity of rhM-CSF detected in the haemolymph was 1 x 10(6) colony-formation units/ml, approximately half of the expression level directed by the native signal peptide of hM-CSF in silkworm larvae. The secreted rhM-CSF was purified to homogeneity. N-terminal analysis showed that the signal peptide had been removed, indicating that insect cells possess the enzymic activity necessary to cleave the pro-alpha-factor leader region from the fusion protein at the carboxy side of Lys-Arg dibasic residues, which is the cleavage site recognized by KEX2 endopeptidase in yeast cells.

The maize mitochondrial MnSODS encoded by multiple genes are localized in the mitochondrial matrix of transformed yeast cells

We recently demonstrated that maize mitochondrial MnSODs are encoded by a differentially expressed multigene family. Molecular characterization of the cloned maize MnSod cDNAs shows that all the maize MnSODs encoded by the cloned MnSod have mitochondrial transit peptides and that the matrix-targeting signal was conserved in all the MnSOD precursor proteins, suggesting that all the maize MnSODs are associated with mitochondria in vivo. In an attempt to clarify the submitochondrial localization of each individual maize MnSOD, each of the maize MnSod cDNAs was introduced into the MnSOD-deficient yeast cells. The functional role and submitochondrial location of each individual MnSOD were examined in the transformed yeast cells. Herein, we demonstrate that all the maize MnSODs can functionally complement the MnSOD deficiency and rescue the transformed yeast cells from oxidative stress induced by paraquat. Biochemical analyses indicate that all of the maize MnSODs are expressed and targeted into the mitochondrial matrix of transformed yeast cells.

[Clinical significance of c-myc gene in esophageal squamous cell carcinoma]

Using polymerase chain reaction, we analysed 41 samples of esophageal squamous cell cancer at molecular level. Amplification of c-myc gene was found in 16 (39%). C-myc gene amplification was found to be related to lymph node metastasis, TNM staging (P < 0.01) and also prognosis (P < 0.05). We thought that c-myc gene was the prognosis factor for the patients with esophageal squamous cell carcinoma.

[A brief history of the Zhejiang Central Hospital and Provincial School of Medicine]

Zhejiang Central Hospital with its affiliated school and Provincial Professional Medical School with its affiliated hospital were the two largest medical schools in modern Zhejiang. It can be seen from their developmental history that the spreading of western medicine exerted considerable influence on Zhejiang region though the areas of its spreading is rather uneven.

Differential distribution of type IV collagen chains in patients with diabetic nephropathy in non-insulin-dependent diabetes mellitus

Thickening of the glomerular basement membrane (GBM) and expansion of the mesangial matrix are hallmarks of human diabetic nephropathy. Renal tissues from 15 patients with type II (non-insulin-dependent) diabetes (NIDDM) were studied by immunofluorescence (IF) and immunogold electron microscopy (IEM) for the distribution of 2 type IV collagen peptides [alpha 3(IV) noncollagenous (NC) domain and alpha 4(IV) NC domain] and 2 classical type IV collagen chains [alpha 1(IV) NC domain and alpha 2(IV) domain]. There was intense staining for alpha 3(IV) NC and alpha 4(IV) NC domain in the GBM but not in the mesangial matrix of patients with overt diabetic nephropathy. In contrast, staining with antibodies to alpha 1(IV) NC and alpha 2(IV) NC domain reacted with mesangial matrix but was significantly decreased in the GBM in the patients with overt diabetic nephropathy. IEM confirmed the IF findings. These data suggest that expansion of the mesangial matrix and thickening of GBM in NIDDM involves separate and distinct type IV collagen components and that the site-specific matrix alterations in NIDDM and type I (insulin-dependent) diabetes are parallel.

[Drug resistant mechanism of clinical isolates of Klebsiella pneumoniae]

Plasmid conjugation experiments of 34 gentamicin-resistant strains of K. Pneumoniae were done. The resistant genes of 31 strains (91%) were transferred partially or completely with a frequency of 10(-4)-10(-6). The results of plasmid analysis in 63 strains of K. Pneumoniae showed that 85kb and 58kb plasmids carrying resistant genes were responsible for bacterial resistance. 13kb plasmids or the smaller ones were not related to bacterial resistance. In spite of the aminoglycoside modifying enzyme, The profiles were different, but the plasmid patterns were almost the same.

Association and linkage with quantitative traits

This paper examines two approaches for the analysis of quantitative traits: (1) association studies and (2) linkage studies. The trait studied was Q1 from simulated Problem 2 data set in Genetic Analysis Workshop 9. Our purpose was to evaluate associations present in the data, to identify nongenetic and genetic predictors of the trait, and to explore the simulated genome for linkage. Through the association study, we found evidence for the primary major gene associated with this trait. The linkage study found evidence of residual genetic effect acting through other traits. Adjustments of Q1 for Q2 and Q3 led to a failure to find significant effects of MG2 and MG3. This supports the suggestion that adjustment for genetically influenced traits for effects of other genetic traits can reduce the power to detect major gene effects. In summary, we detected the major gene directly associated with the trait of interest through association studies. Linkage analysis detected evidence for two other genes associated to a lesser degree with the trait.

Expression of a biologically active human granulocyte-macrophage colony stimulating factor fusion protein in Escherichia coli

A gene encoding human granulocyte-macrophage colony stimulating factor(GM-CSF), was cloned into plasmid pEZZ318 and fused to a DNA segment coding for the signal peptide of staphylococcal protein A and a synthetic gene coding for a protein with ability to bind immunoglobulin G(IgG). The fusion protein was expressed in Escherichia coli and biologically actively secreted into the growth medium. Approximately all of the total activity was secreted into the culture medium, where levels of activity approached 1.96 x 10(8) units/liter. Purification of the fusion protein was performed in a single step by affinity chromatography with immobilized IgG to a specific activity of 1.2 x 10(8) units/mg.

Expression and purification of a truncated macrophage colony stimulating factor in Kluyveromyces lactis

A truncated human macrophage colony stimulating factor (M-CSF) cDNA encoding amino acid residues from 3 to 149 of the native M-CSF was obtained by using polymerase chain reaction. When inserted into plasmid pCXJ1 and psPHO5 and introduced into Kluyveromyces lactis, it directs the the secretory expression of the biologically active dimeric form of M-CSF. Through a four-step purification protocol, i.e. ammonium sulfate salting out, DEAE-cellulose column chromatography, hydrophobic chromatography on phenyl-sepharose and Mono Q fast protein liquid chromatography, the recombinant truncated M-CSF was purified to homogenerity and show its apparent molecular mass at 21KDa on reduced SDS-PAGE, with a specific activity of 1.21 x 10(7) units/mg protein.

Differential Accumulation of Manganese-Superoxide Dismutase Transcripts in Maize in Response to Abscisic Acid and High Osmoticum

The plant growth regulator abscisic acid (ABA) has multiple physiological effects during embryogenesis and seed formation. Although a number of genes induced by ABA have been characterized, the functions of the encoded proteins remain, for the most part, obscure. In this paper we demonstrate that members of the manganese-superoxide dismutase (MnSod) gene family encoding antioxidant isozymes of known function during development and oxidative stress respond differentially to ABA and high osmoticum in developing maize (Zea mays L.) embryos. Expression of the maize Sod3.1 does not respond to ABA or high osmoticum, whereas the steady-state levels of the maize Sod3.2, Sod3.3, and Sod3.4 transcripts are induced by ABA. Total SOD-3 protein and enzymatic activity, however, remain constant. Additionally, we examined the requirement for ABA in the accumulation of MnSod transcripts in response to high osmoticum in wild-type and mutant embryos of an ABA-deficient line (M1A4; vp5). RNA blot analyses show that multiple Sod3 transcripts are also found in line M1A4, and ABA increases the accumulation of the Sod3.2, Sod3.3, and Sod3.4 transcripts in both wild-type and vp5 mutant embryos. Interestingly, although accumulation of the Sod3.3 and Sod3.4 transcripts in the vp5 mutant embryo was induced by ABA, it was not induced by high osmoticum. Both superoxide dismutase and ABA have been implicated in plant tolerance to environmental stress; results from this study demonstrate a connection between the action of ABA and oxidative stress during embryo maturation in maize.

[Soluble interleukin-2 receptor level in the sera and ascitic fluids in patients with ovarian cancer]

In 31 patients with ovarian cancer, the sIL-2R level of the sera and ascitic fluids were measured by ELISA, to investigate the inhibitive effect of sIL-2R purified from ascitic fluids on normal lymphocyte transformation, stimulated with phytohemagglutinin (PHA). The results showed that the sera sIL-2R levels in the patients were much higher than those in the normal controls (857 +/- 428kU/L vs 235 +/- 90kU/L, P < 0.001). The sera sIL-2R levels in mucinous cancer were significantly higher than those in serous cancer (988 +/- 539kU/L vs 488 +/- 233kU/L P < 0.01). But no obvious correlation was observed with the histopathological grading, nor with metastasis. Higher levels of sIL-2R were also observed in the ascitic. The normal lymphocyte transformation stimulated with PHA was significantly inhibited by high sIL-2R purified from the ascitic fluids.

Expression of a fibrinolytically active human pro-urokinase fusion protein in Escherichia coli

The gene encoding human pro-urokinase(pro-UK) was cloned into plasmid pEZZ318 and fused to the gene coding for the signal peptide of staphylococcal protein A and IgG bindinging domain. The fusion protein which was synthesized under the control of T7 promoter in Escherichia coli and secreted into the growth medium, was found to be fibrinolytically active. Approximately 60% of the total activity was secreted into the culture medium, where levels of activity approached 150,000 I.U./liter and about 40% of the total activity remained in the cell lysate with levels of activity around 100,000 I.U./liter. The fusion protein was purified in a single step by IgG affinity chromatography. These results demonstrate that human pro-UK can be synthesized and secreted by E. coli as a fibrinolytically active fusion protein.

Rapid mRNA degradation in yeast can proceed independently of translational elongation

We have exploited a modular cat reporter system (Vega Laso, M. R., Zhu, D., Sagliocco, F. A., Brown, A. J. P., Tuite, M. F., and McCarthy, J. E. G. (1993) J. Biol. Chem. 268, 6453-6462) to investigate the relationship between mRNA structure, translation, and stability in the yeast Saccharomyces cerevisiae. The stability of the cat mRNA was not influenced by changes in the length and nucleotide sequence of the 5'-leader, but was affected by the formation of stable 5'-secondary structures (> -15 kcal.mol-1). Cat mRNA stability changed only slightly when the CYC1 3'-trailer was replaced with PGK1 sequences, and was influenced by some secondary structures in the 3'-trailer. Secondary structures formed by interactions between the 5'-leader and 3'-trailer increased the stability of the cat mRNA. However, all of the cat mRNAs studied were intrinsically unstable, having half-lives between 4 and 14 min. The translatability of the cat mRNAs did not correlate with their half-life, and their decay was not blocked by cycloheximide. Therefore, the rapid degradation of the cat mRNA does not seem to depend on translational elongation and is not related in any obvious way to the rate of translational initiation. Furthermore, sequences in the 3'-trailer do not program the rapid decay of the cat mRNA. We discuss the implications of these data in the light of current models of mRNA degradation pathways.

[Local recurrence after conservative therapy of breast cancer: risk factors, site of recurrence, evolution]

The identification of factors associated with breast recurrence as first event (62 cases, 10%) following conservative surgery and radiation therapy are drawn out from a series++ of 618 mammary carcinomas of clinical size less than 40 mm, stage I and II (UICC), with a median follow up of 8 years. The most powerful predictive characteristic associated with the likelihood of breast recurrence is multiple foci of invasion (42.9% vs 8.9, P = 0.0001, relative risk [RR]: 6). After this rarely cited feature, young age, less than 40 years (20% vs 7.3%, P = 0.0001, RR: 2.8), extensive in situ carcinoma more than 25% (19.2% vs 8.7%, P = 0.003, RR: 2.5) were found also persistent in the Cox model, but not histologic size more than 25 mm (18.9% vs 9.1%, P = 0.01, RR: 2.3). The site of recurrence was studied on the 54 salvage mastectomy done. A high rate of recurrence at distance of the initial site was found: 37% whose more than half, 22%, were multicentric. No significant difference in the mean delay of appearance was noted between recurrence near or at distance of the initial cancer (mean delay 52 months vs 64 months). From the recurrence the evolution is not very favourable: excluding simultaneous metastases found at the preoperative investigation, ten cases, mammary recurrence is followed by a metastatic syndrome in 36% of cases against 17% without it (P = 0.01, RR: 1.9). Metastatic evolution is not significantly linked with the time, early or late, of the mammary recurrence (54.5% before 5 years vs 39% after) but with the association of a controlateral cancer (P = 0.03). Locally ten of the 54 mastectomy presented a thoracic recurrence, often in case of multicentric breast recurrence (P = 0.05) and not significantly when skin or areola were invaded by carcinoma.

Sequence evolution and phylogenetic signal in control-region and cytochrome b sequences of rainbow fishes (Melanotaeniidae)

The nucleotide sequences of segments of the cytochrome b gene (351 bp), the tRNA(Pro) gene (49 bp), and the control region (approximately 313 bp) of mitochondrial DNA were obtained from 26 fish representing different populations and species of Melanotaenia and one species of Glossolepis, freshwater rainbow fishes confined to Australia and New Guinea. The purpose was to investigate relative rates and patterns of sequence evolution. Overall levels of divergence were similar for the cytochrome b and tRNA control-region sequences, both ranging from < 1% within subspecies to 15%-19% between genera. However, the patterns of sequence evolution differed. For the cytochrome b gene, transitions consistently exceeded transversions, the bias ranging from 4.2:1 to 2:1, depending on the level of sequence divergence. However, in the control-region sequence, a bias toward transitions (2:1) was observed only in comparisons between very similar sequences, and transversions outnumbered transitions in comparisons of divergent sequences. Graphic comparisons suggested that the control region was saturated for transitions at relatively low levels of sequence divergence but accumulated transversions at a greater rate than did the cytochrome b sequence. These distinct patterns of base substitution are associated with differences in A+T content, which is 70% for the tRNA control-region segment versus 50% for cytochrome b. A test for skewness in the distribution of lengths of random trees indicated that both segments contained phylogenetic signal. Parsimony analyses of the data from the two regions, with or without weighting schemes appropriate to the respective patterns of sequence evolution, identified the same five groupings of sequences, but the relationships among the groups differed. However, in most cases the branches uniting different combinations of groups were poorly supported, and the differences among topologies were insignificant. Considering the observed patterns of base substitution and the results of the phylogenetic analyses, we deduce that both the control region and cytochrome b are appropriate for population genetic studies but that the control region is less effective than cytochrome b for resolving relationships among divergent lineages of rainbow fishes.

Electrostatic interactions in collagen-like triple-helical peptides

Collagen-like peptides with potential for ion pair formation were studied to investigate the role of electrostatic interactions in the triple-helix conformation. Three peptides--(POG)10, the EK-containing peptide (POG)4EKG(POG)5, and T3-487, a peptide with 18 residues of type III collagen and a C-terminal (GPO)4 tail--all form stable triple helices in aqueous solution, with melting temperatures of 58, 46, and 26 degrees C, respectively, at neutral pH. The thermal stabilities of these peptides correlate with their imino acid content, which is 66%, 60%, and 41%, respectively. Variation of pH over the range of 1-13 led to 8-9 degrees C changes in the Tm of the EK-containing peptide and peptide T3-487, with the greatest stability seen at pH values where both acidic and basic residues are ionized. Equilibrium ultracentrifugation shows these peptides are largely trimeric at low temperature, with no hexamers or larger aggregates, indicating that the pH-dependent stability arises from intramolecular interaction. Computer modeling indicates both intrachain ion pairs and interchain ion pairs can form and stabilize the triple helix. Studies of the pH dependence of the thermal stability of (POG)10 and the N-terminal acetylated form of T3-487 indicate that repulsion of the three charged N-terminal or C-terminal ends has a destabilizing effect. Taking into account these end effects, the energy contribution of two oppositely charged residues in a triple helix which are sterically capable of participating in ion pairs and backbone hydrogen bonding is 0.5-1 kcal/mol ion pair. It is possible that the stabilizing influence of ion pairs arises indirectly, through elimination of like charge repulsion, formation of ion pairs in the single chain form, or solvent effects.

Idiotypic vaccination against human B-cell lymphoma. Rescue of variable region gene sequences from biopsy material for assembly as single-chain Fv personal vaccines

Idiotypic determinants on neoplastic B cells could provide tumor antigens for vaccination of patients with B-cell tumors. Because this approach requires an individual vaccine for each patient, simple methods for obtaining idiotypic antigen are desirable. Using polymerase chain reaction (PCR) with family-based V-gene and J-region primers, the variable region genes of heavy and light chains (VH and VL) of Ig have been obtained from biopsy material from 13 patients with B-cell tumors. In each case, analysis of random clones derived from the PCR product showed repeated, clonally-related sequences, whereas normal lymphoid tissue generated no repeated sequences. In 3/3 cases, the repeated sequences were found to be the same as those in a tumor-derived hybridoma. Mutational patterns in the V-genes differed among the tumors, with follicular lymphoma tending to be more highly mutated. The individual VH and VL sequences have been assembled with a flexible linker sequence to encode single-chain Fv (scFv). The scFv sequences can be cloned into bacterial expression vectors to produce protein, or into vectors suitable for direct vaccination using naked DNA. In a model system, expressed scFv protein retained all idiotypic determinants defined by a panel of five anti-idiotypic monoclonal antibodies (MoAbs). Similarly, expressed scFv proteins from two patients were shown to react with anti-idiotypic antibodies. This approach allows production of potential vaccines from surgical biopsies within 2 to 3 weeks.

Expression of biologically active monomeric form of human M-CSF in baculovirus infected silkworm, Bombyx mori

The human macrophage colony stimulating factor (hM-CSF) in its monomeric form has been over-produced in BmN cells and in silkworm larvae infected with the recombinant baculovirus Bm284M-CSF. The recombinant monomeric M-CSF (rhM-CSF) exhibited the activity of 8-14 x 10(4) units/ml of cell culture medium. When the insect larvae were infected with the recombinant virus, the maximum rhM-CSF was expressed 4-5 days post infection with an activity of 3 x 10(6) units/ml hemolymph. The monomeric rhM-CSF was purified to homogeneity through three steps of purification. A pilot purification yielded 1 mg of homogeneous monomeric rhM-CSF from 10 larvae. The purified rhM-CSF monomers gradually dimerized in vitro. In contrast, the crude or the semi-purified monomers did not dimerize in vitro, indicating that the presence of an unknown moiety in the rhM-CSF preparations obtained from hemolymph interfered with dimerization.

Application of electron microscopic immunocytochemistry to the human kidney: distribution of type IV and type VI collagen in normal human kidney

We used immunogold electron microscopic (IEM) techniques with periodate-lysine-paraformaldehyde-fixed and Lowicryl-embedded or cryopreserved tissues to study the distribution of alpha 1(IV) and alpha 3(IV) chains of Types IV and VI collagen in glomerular basement membrane (GBM) and mesangial matrix of glomeruli in normal human kidneys. Monoclonal antibodies to alpha 1(IV) and alpha 3(IV) collagen chains and Type VI collagen could be detected only with cryoultramicrotomy, whereas polyclonal anti-Type IV collagen antibody was detectable in Lowicryl-embedded tissue. Ultrastructural detail was better preserved in the Lowicryl-embedded tissue. IEM labeling provided more detailed information as to the site-specific array of these extracellular matrix molecules in glomeruli than did immunofluorescent microscopy. The labeling of alpha 1(IV) collagen chain was distributed mainly along the endothelial side of glomerular basement membrane and the mesangial matrix. Mesangial GBM was relatively poorly labeled compared with that of mesangial matrix. In contrast, the alpha 3(IV) chain was detected throughout the thickness of the GBM, but there was no labeling of mesangial matrix. Type VI collagen distribution was identical to that of the alpha 1(IV) chain within the glomerulus but was also associated with interstitial collagen fibrils. This study documents and details the heterogeneous distribution of Type IV and VI collagen chains within the normal human glomerulus and provides the framework for the study of these matrix components in human glomerular diseases.

Prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency by allele-specific hybridization and Southern blot

The feasibility and accuracy of gene-specific molecular genetic diagnosis for congenital adrenal hyperplasia due to 21-hydroxylase deficiency was studied in a group of 24 pregnancies at 25% risk of carrying an affected fetus. Chorionic villus sampling was performed at 9-10 weeks' gestation. Southern analysis and polymerase chain reaction, followed by allele-specific hybridization for a panel of nine known mutations, were performed for each family. Mutations were identified in 95% of chromosomes examined; the molecular diagnosis was accurate in 96% of infants as confirmed by postnatal examination. The most common mutation identified was an A-to-G transition at base 656 in the second intron, the result of an apparent gene conversion. In one family, there had been a de novo mutation in intron 2, which was detected in the proband, but not in the mother or in the fetus. We conclude that first trimester prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency is feasible and accurate employing CYP21-specific probes.

Enhancement of expression of human granulocyte-macrophage colony stimulating factor by argU gene product in Escherichia coli

Human granulocyte-macrophage colony stimulating factor (hGM-CSF) was cloned into expression vector pIN III-ompA1 and expressed in Escherichia coli JA221. When supplementation with a minor tRNA(AGA/AGG)Arg encoded by the E. coli argU gene, the expression level of hGM-CSF was raised about 3-4-fold, although there is only one rare AGG codon in hGM-CSF cDNA gene.

Clonal history of a human follicular lymphoma as revealed in the immunoglobulin variable region genes

The variable region genes used to encode the immunoglobulin expressed by tumour cells of a patient with follicular lymphoma have been identified and sequenced. Initially, a lymph node biopsy was analysed and revealed usage of VH and V kappa genes which had numerous substitutions as compared with the closest germ line genes. The pattern of mutations in VH was consistent with a role for positive selection by antigen. In addition, there was evidence in both VH and V kappa sequences for clonal heterogeneity. After 5 years, which included treatment with chemotherapy, the patient relapsed with tumour cells present in the blood. Analysis of the V-genes used by the emerging tumour revealed a single homogeneous sequence for both VH and VL, which, in each case, matched closely one of the sequences in the original lymph node biopsy. These results indicate that selection, possibly mediated by antigen, can operate on a cell destined to give rise to lymphoma, and that intraclonal variation can occur after the neoplastic event. However, in this case, late relapse in the blood is dominated by a single clone.

Properties of three proteinases functioning at G1, S and G2 phases in HeLa cells and their inhibition by guanidino- and amidino-acid esters

HeLa cells were synchronized by double thymidine-block and allowed to grow after removal of thymidine. Three proteinases, tryptase 17:17, proteinase In and late G2 proteinase, were prepared from the HeLa cells harvested at the time when each proteinase appeared in the cell cycle of the cells. All of them were suggested to be trypsin-like serine proteinases, because they hydrolyzed trypsin-specific fluorogenic substrates and their activities were inhibited by benzamidine, soybean trypsin inhibitor, leupeptin, tosyl-L-lysine chloromethan (TLCK) and diisopropylfluorophosphate (DEP). However, the actions of these proteinases on the substrates and inhibitors suggested that they were three different proteinases. They were strongly inhibited by 4-tert-butylphenyl and biphenyl esters of trans-4-guanidinomethylcyclohexanecarboxylic acid, amidinopiperidine-4-acetic and 4-propionic acids, which retard the second DNA synthetic (S) and mitotic (M) phases for 3h, 4-tert-butylphenyl ester of amidinopiperidin-4-carboxylic acid, which blocks initiation of S phase, the ester of amidinopiperidine-4-butyric acid, which suppresses the second S and M phases, and the esters of trans-4-amidinocyclohexanecarboxylic and 4-propionic acids which inhibit M phase.

Glomerular distribution of type IV collagen in diabetes by high resolution quantitative immunochemistry

We examined type IV collagen distribution and density in human diabetic kidneys by quantitative immunogold electron microscopy. We studied normal kidney transplant donors and "slow-track" and "fast-track" insulin dependent diabetic (IDDM) patients. The "slow-track" patients had IDDM for > or = 20 years and mesangial volume fraction (VvMes/glom) of < or = 0.32. The "fast-track" patients had IDDM for < or = 20 years and VvMes/glom > or = 0.37. Renal biopsies were embedded in Lowicryl, reacted with polyclonal anti-type IV collagen (in the distribution of the classical alpha 1(IV) and alpha 2(IV) collagen chains) and monoclonal anti-alpha 4(IV) collagen chain antibody followed by gold conjugated secondary antibody. We found, by morphometric techniques, a decrease in the immunogold densities of anti-type IV collagen in the subendothelial zone of the GBM in the "fast-track" IDDM patients. There was a trend towards a decrease in mesangial matrix (MM) particle density in the "fast-track" (P = 0.07) but not in the "slow-track" patients. However, because of the marked increase in MM in the "fast-track" patients, the per glomerulus estimated quantity of these antigens in MM was increased. In contrast, the density of alpha 4(IV) collagen chain was increased in the epithelial zone of the GBM in the "fast-track" IDDM patients. It is not known whether these changes in glomerular type IV collagen represent markers of advanced diabetic lesions or whether these changes might be detected earlier in diabetic patients destined for the later development of serious lesions.

Molecular genetic prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency by allele-specific hybridization

The feasibility and accuracy of gene-specific molecular genetic diagnosis for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency were studied in a group of 24 pregnancies at 25% risk of carrying an affected fetus. Chorionic villus sampling was performed in the majority of cases. Southern blot analysis was carried out to identify deletions or other gross rearrangements. In parallel, the polymerase chain reaction (PCR) was performed, followed by allele-specific oligonucleotide hybridization (ASO) for a panel of nine known mutations. Mutations were identified in 95% of the chromosomes examined. The molecular diagnosis was accurate in 23 of 24 infants. The most common mutation identified was an A-to-G transition in the second intron (52% of affected chromosomes), the result of an apparent gene conversion. One fetus carried homozygous deletion of CYP21, which accounted for 13% of all affected chromosomes. Other mutations identified included an 8-bp deletion in the third exon (22%); Ile172 to Asn, a nonconservative substitution, in the fourth exon (9%); and Gln318 to term, a nonsense mutation, in the eight exon (4%). No mutation was detected in CYP21 in 5% of obligate-affected chromosomes examined by these methods.

Differential induction of human monocyte transforming growth factor beta 1 production and its regulation by interleukin 4

We have previously shown that trauma patients' monocytes which are in vivo activated by multiple injury-induced mediators have elevated transforming growth factor-beta (TGF beta) bioactivity. Interleukin-4 (IL-4), a Th2 and B lymphocyte stimulatory factor, has been shown to inhibit monocyte production of a number of mediators both after lipopolysaccharide stimulation and after trauma-induced stimulation. However, IL-4 inhibitory effects appears to vary, depending on the mixture of inducing stimuli. Here we describe the in vitro IL-4 inhibition of human monocyte TGF beta bioactivity using several stimulation induction protocols: muramyl dipeptide stimulation alone, or after Fc gamma RI (CD64) cross-linking induction, interferon-gamma (IFN gamma) priming, or trauma-generated in vivo mediator induction. IL-4 suppressed both muramyl dipeptide-induced TGF beta bioactivity and TGF beta mRNA in a dose-dependent fashion and was most effective when IL-4 was administered at initiation of normal monocyte stimulation. Muramyl dipeptide (MDP)-induced increases in trauma patients' monocyte TGF beta bioactivity were also inhibited by high doses of IL-4 (25 ng/ml). Fc gamma RI cross-linking increased MDP-induced normal monocyte TGF beta bioactivity, but this increase could be consistently inhibited only by very high IL-4 concentrations (50 ng/ml). IL-4 did not consistently downregulate MDP-induced TGF beta bioactivity in IFN gamma-primed monocytes. IL-4 can suppress monocyte TGF beta production, as well as other monocyte mediators, but its efficiency depends on the stimuli combination present in the microenvironment.

The influence of 5'-secondary structures upon ribosome binding to mRNA during translation in yeast

The influence of 5'-secondary structure formation and 5'-leader length upon mRNA translation in yeast has been analyzed using a closely related set of cat mRNAs (Vega Laso, M. R., Zhu, D., Sagliocco, F. A., Brown, A. J. P., Tuite, M. F., and McCarthy, J. E. G. (1993) J. Biol. Chem. 268, 6453-6462). A cat mRNA with a relatively short unstructured 5'-leader (22 bases) had a ribosome loading about half that of a cat mRNA with an unstructured 5'-leader of 77 bases. The introduction of 5'-secondary structures at various positions throughout the 5'-leader of the cat mRNA inhibited translation initiation, the degree of inhibition being largely dependent upon the thermodynamic stability of the structure. Each mRNA carrying a 5'-secondary structure had a biphasic polysome distribution, indicating that the mRNA molecules were distributed between untranslated and well translated subpopulations. This suggests that once 5'-secondary structures are unwound, they reform slowly relative to the rate of translation initiation in yeast. Untranslated mRNA accumulated in 43 S preinitiation complexes, even when there were only 5 bases between the 5'-cap and the base of the hairpin. The data are consistent with the scanning hypothesis (Kozak, M. (1989) J. Cell. Biol. 108, 229-241) and suggest that 40 S ribosomal subunits bind to mRNA early in the scanning process, probably before mRNA unwinding has taken place.

Characterization of collagen-like peptides containing interruptions in the repeating Gly-X-Y sequence

Glycine is found as every third residue along the entire length of triple helices in fibrillar collagens, but the triple-helix regions of nonfibrillar collagens and other proteins usually contain one or more interruptions in this repeating pattern. A set of four peptides was designed to model the effect of interruptions in the (Gly-X-Y)n repeating pattern on triple-helix formation, stability, and folding. Into the middle of the stable triple-helical peptide (Pro-Hyp-Gly)10, an interruption was introduced representing one of the four possible categories: a glycine deletion, a deletion of a hydroxyproline (Y position), an alanine insertion, or a glycine to alanine substitution. As shown by sedimentation equilibrium, NMR, and CD studies, the introduction of an interruption still allowed formation of trimers in solution, but with marked decrease in stability. The degree of destabilization and the thermodynamic basis for the loss of stability depended on the type of interruption. The glycine substitution and alanine insertion were the least disruptive, followed by the hydroxyproline deletion, with the glycine deletion being the most destabilizing. Our results suggest that the breaks in these peptides affect both the triple-helical conformation and the monomer conformation. These studies provide a basis for considering the structural and functional consequences of different kinds of interruptions in collagen.

Alterations in the synthesis of insulin-like growth factor binding proteins and insulin-like growth factors in rat C6 glioma cells transfected with a gap junction connexin43 cDNA

When C6 glioma cells are stably transfected with a connexin43 cDNA and gap junctions are increased, the rate of cellular proliferation is decreased. To determine if this phenomenon is related to alterations in IGFBP and IGF synthesis, we have compared IGFBPs and IGFs in the conditioned media from primary rat astroglia, C6, and transfected C6 clones Cx43-13 (high expresser), and Cx43-12 and Cx43-14 (intermediate expressers). Primary astroglia produced IGFBP-2 (34 kDa) and IGFBP-3 (40-45 kDa). C6 cells synthesized high levels of IGFBP-3 and low levels of IGFBP-2, and a 24 kDa IGFBP (IGFBP-4). Cx43-13 cells did not synthesize IGFBP-3, but produced low levels of IGFBP-2 and high levels of IGFBP-4. Cx43-12 and Cx43-14 secreted IGFBP profiles similar to the parent C6 line, but with reduced levels of IGFBP-2. The lack of IGFBP-3 in Cx43-13 cells was not due to the presence of proteases. Northern analysis showed IGFBP-2 mRNA to be readily detectable only in the primary astroglia. IGFBP-3 mRNA was detected in the primary astroglia, C6, Cx43-12 and Cx43-14, but not in Cx43-13. In contrast, IGFBP-4 mRNA was readily detected only in the Cx43-13. IGF-II concentrations in the media were low to undetectable for both C6 and transfected cells. IGF-I concentrations were significantly lower in the media from transfected cells compared to the C6 cells. Stable mRNA levels for IGF-I were lower in transfected cells, with the lowest levels observed in the Cx43-13 cells. Although C6 cells did not respond mitogenically to exogenous IGF-I or IGF-II, Cx43-13 cells responded to IGF-I or IGF-II in a dose dependent manner. Conditioned media from Cx43-13 cells decreased the DNA synthesis of C6 cells, and this effect could be reversed by the addition of IGF-II. The decreased synthesis of the autocrine/paracrine growth factor IGF-I together with decreased levels of a positive modulator IGFBP-3, and the increased levels of a negative modulator IGFBP-4 in the extracellular milieu, may be responsible for the reduced proliferative capacity in cells expressing abundant connexin43.

Maize mitochondrial manganese superoxide dismutases are encoded by a differentially expressed multigene family

We have isolated maize cDNAs encoding three manganese-containing superoxide dismutases (MnSODs) distinct from the one previously reported. Molecular analyses indicate that multiple MnSOD transcripts are encoded by different, though similar, genes in the maize genome. A single MnSOD gene has been reported in all other organisms examined to date. The deduced amino acid sequences show that these maize MnSOD proteins have a mitochondrial transit peptide and that the first 9 amino acids (matrix-targeting sequence) in the transit peptide are conserved. This suggests that all the maize MnSOD proteins are mitochondria-associated isozymes. RNA blot analysis demonstrated that each member of the maize MnSOD multigene family is both spatially and developmentally regulated. One gene, Sod3.3, was predominantly expressed in the embryo late in embryogenesis. Patterns of increased Mn-SOD transcript accumulation are shown to be associated with increased mitochondrial activity during plant growth and development. The influence of mitochondrial metabolism on the expression of the nuclear MnSOD genes is discussed.

Lung endothelial dipeptidyl peptidase IV is an adhesion molecule for lung-metastatic rat breast and prostate carcinoma cells

Attachment of circulating tumor cells to endothelial cell adhesion molecules restricted to select vascular compartments is thought to be responsible for site-specific metastasis. Lung-metastatic rat R3230AC-MET breast and RPC-2 prostate carcinoma cells bound outside-out endothelial cell membrane vesicles, prepared by perfusion of the rat lung vasculature with a low-strength formaldehyde solution, in significantly higher numbers than their nonmetastatic counterparts R3230AC-LR and RPC-LR. In contrast, vesicles derived from the vasculature of a nonmetastasized organ (e.g., hind leg muscle) showed no binding preference for either of the four tumor cell lines. Lung-derived endothelial vesicles were used here to generate mAbs against lung endothelial cell adhesion molecules. The first group of mice were actively immunized against lung endothelial vesicles, whereas the second group was injected with syngeneic mouse antiserum against leg endothelial vesicles before active immunization with lung endothelial vesicles. 17 hybridoma supernatants obtained from the two fusions bound lung vesicles with at least a 10-fold higher affinity than leg vesicles. Seven (four obtained by a passive/active immunization protocol) stained rat capillary endothelia. One mAb, mAb 8.6A3, inhibited specific adhesion of lung-derived vesicles to lung-metastatic breast and prostate carcinoma cells. Purification of the antigen (endothelial cell adhesion molecule) from rat lung extracts revealed a protein with a 110-kD mol wt. NH2-terminal sequencing established identity with dipeptidyl peptidase IV which had been reported to serve as a fibronectin-binding protein. These results indicate that vesicles obtained from in situ perfused organs are a convenient immunogen for the production of antibodies to compartment-specific endothelial cell surface molecules, and reinforce the concept that endothelial cell surface components are selectively recognized by circulating cancer cells during metastasis formation.

Ultrastructural analysis of gap junctions in C6 glioma cells transfected with connexin43 cDNA

In the past, we transfected C6 glioma cells with connexin43 cDNA, resulting in a significant increase in connexin43 mRNA and protein, as well as reduced proliferation and tumorigenesis. To investigate the morphological aspects of increased connexin43 expression in these cells, we have used a combination of immunocytochemistry, cytochemistry, and electron microscopy. By confocal immunofluorescence microscopy, connexin43 protein was localized to the plasma membrane of transfected cells and extensive intracellular accumulations of connexin43 were also demonstrated. Freeze fracture preparations showed large aggregates of particles typical of mature gap junction plaques in the plasma membrane of these cells. Ultrastructural immunogold labeling with anti-connexin43 serum revealed that connexin43 protein was present in gap junctions in the plasma membrane, some of which were found in proximity to clathrin-coated pits. In addition, various intracellular membranous profiles were immunoreactive for connexin43, including annular profiles, some with fuzzy coats and some associated with lysosome-like structures. Enzyme cytochemistry revealed that these annular gap junction profiles were often associated with acid phosphatase-positive lysosomes. These studies on the intracellular localization of gap junction protein in connexin43-transfected cells are consistent with the functional expression of the transfected connexin43 cDNA and provide a useful model to study the pathways of gap junction assembly and degradation.

Inhibition of translational initiation in the yeast Saccharomyces cerevisiae as a function of the stability and position of hairpin structures in the mRNA leader

A new modular in vivo/in vitro expression system was constructed which facilitates studies of the control and regulation of gene expression in the yeast Saccharomyces cerevisiae. We studied the influence of stem-loop structures inserted into the non-translated leader region upon the steady-state levels and translation of mRNAs bearing the cat gene from the bacterial transposon Tn9. mRNA abundance changed relatively little in response to alterations in the leader sequence and structure, whereas stem-loop structures clearly inhibited translation to a degree that was dependent upon the predicted stability as well as the position of the inserted secondary structure. A stem-loop structure with a predicted stability greater than -28 kcal mol-1 and with a stem comprising at least 15 (mainly G/C) base pairs inhibited translation in vivo by at least 98%. A stem-loop structure with a predicted stability of approximately -14 kcal mol-1, whose stem comprised at least six G/C base pairs, inhibited translation in vivo by at least 66%. The hairpins were more inhibitory when placed close to the start codon than when positioned near the 5' end of the leader. An mRNA showing extensive complementarity between the leader and trailer regions was not only poorly translated but also had a steady-state level at least three times higher than the average for all the cat constructs examined. Translation of the various mRNAs in a yeast cell-free system followed qualitatively the same pattern as the results obtained in vivo. The stem-loop structures were far less inhibitory in a reticulocyte lysate system. Overall, the data are likely to reflect the full spectrum of translational activities of yeast mRNAs in vivo determined by secondary structure and emphasize the importance of translation as a control step in gene expression.

Insulin-like growth factor binding protein-4 gene expression is induced by transfection of gap junction connexin43 gene in a C6 glioma cell line

When C6 glioma cells are stably transfected with a connexin43 cDNA and the gene overexpressed, the rate of cellular proliferation is decreased. To determine if this phenomenon is related to alterations in IGFBP synthesis, we have compared the conditioned media of primary rat astroglia, C6, clones Cx43-13 (high expresser of the transfected connexin43 gene), and Cx43-12 and Cx43-14 (intermediate expressers). Primary astroglia produced IGFBP-2 (M(r) 34 K) and IGFBP-3 (40-45 K). C6 cells synthesized high levels of IGFBP-3 and low levels of IGFBP-2, and a 24 K IGFBP (IGFBP-4). Cx43-13 cells did not synthesize IGFBP-3, but produced low levels of IGFBP-2 and high levels of IGFBP-4. Cx43-12 and Cx43-14 secreted IGFBP profiles similar to the parent C6 line, but with reduced levels of IGFBP-2. Northern analysis showed the changes in IGFBPs in the conditioned media to be correlated with alterations in stable mRNA levels. IGFBP-4, a inhibitor of IGF biological action, was produced in greater quantities by the slowly proliferating Cx43-13 cells. Alterations in IGFBP-4 synthesis may be responsible, at least in part, for the reduced proliferative capacity in cells with abundant connexin43.

Correlation between the lung distribution patterns of Lu-ECAM-1 and melanoma experimental metastases

Lu-ECAM-1 is a 90-kDa lectin-like, melanoma-cell-binding endothelial-cell adhesion molecule that mediates colonization of the lungs by B16-F10 melanoma cells. The well-known formation of pleural and sub-pleural B16-F10 melanoma colonies is correlated quantitatively with prominent histochemical staining of endothelia of pleural capillaries and sub-pleural venules with anti-Lu-ECAM-1 MAb 6D3. The less frequent endothelial staining of perivenous and peribronchial venules is associated with fewer B16-F10 colonies in these locations, and the occasional segmental staining of pulmonary veins coincides with rare tumor nodules which usually expand in an asymmetric fashion around these veins. Lu-ECAM-1 is also expressed on endothelia of some tumor vessels, indicating that these vessels are recruited from the same host blood vessels that originally caused the arrest of blood-borne B16-F10 melanoma cells. The close association between the lung distribution patterns of Lu-ECAM-1-positive blood vessels and experimental melanoma metastases is further evidence of the importance of endothelial-cell adhesion molecules in the formation of metastases.

The left ventricle affects the duration of right ventricular ejection

OBJECTIVE

The aim was to determine if rapid changes in left ventricular pressure can acutely alter right ventricular systolic pressure and thus influence the length of right ventricular ejection.

METHODS

The experiments were performed in six open chest anaesthetised dogs, weight 18-25.5 kg. Left and right ventricular pressures and pulmonary blood flow were recorded continuously as left ventricular pressure was abruptly decreased by opening a shunt in systole. From these data, the pressure and flow changes and the duration of right ventricular ejection were determined.

RESULTS

Opening the left ventricular shunt caused left ventricular pressure to fall from 94.1(SD 10.5) to 62.6(11.3) mm Hg (p < 0.01), right ventricular pressure to fall from 30.3(4.6) to 27.0(3.6) mm Hg (p < 0.01), and pulmonary flow to fall from 69.5(14.2) to 57.5(13.9) ml.s-1. The duration of right ventricular ejection, determined from pulmonary flow, also decreased from 192.7(22.7) to 157.2(18.7) ms (p < 0.05) and was significantly related to the length of left ventricular systole. Time between end diastole and peak negative dP/dt decreased for both left and right ventricle. Left and right ventricular time intervals were related before (r = 0.99) and after (r = 0.75) opening the shunt.

CONCLUSIONS

The duration of right ventricular ejection was decreased by a sudden decrease in left ventricular afterload and was significantly related to the length of left ventricular systole. The duration of right ventricular ejection may be coupled with left ventricular contraction through ventricular interdependence.

Molecular genetic analysis in autosomal dominant keratoconus

Members in three generations of a family whose propositus had keratoconus were examined by biomicroscopy, with a corneoscope and a computer-assisted videophoto-keratoscope. Keratoconus was detected in eight of 15 family members with vertical transmission consistent with autosomal dominant inheritance. Affected individuals displayed variable topographic features. Abortive "nipple-type" cones were identified in some individuals in successive generations using the computer-assisted videophotokeratoscope and more advanced nipple-type cones detected on biomicroscopy of other family members. We selected a COL6A1 cDNA (the gene encoding the alpha 1 chain of type VI collagen) as a "candidate gene" to determine cosegregation with the disease locus. Linkage analysis excluded a gene locus for keratoconus on the most telomeric region of chromosome 21 in this family.