The dichotomous size variation of human complement C4 genes is mediated by a novel family of endogenous retroviruses, which also establishes species-specific genomic patterns among Old World primates

The human complement C4 genes in the HLA exhibit an unusual, dichotomous size polymorphism and a four-gene, modular variation involving novel gene RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin-like Gene X (RCCX). The C4 gene size dichotomy is mediated by an endogenous retrovirus, HERV-K(C4). Nearly identical sequences for this retrotransposon are present precisely at the same location in the long C4 genes from the tandem RCCX Module I and Module II. Specific nucleotide substitutions between the long and short C4 genes have been identified and used for diagnosis. Southern blot analyses revealed that HERV-K(C4) is present at more than 30 locations in the human genome, exhibits variations in the population, and its analogs exist in the genomes of Old World primates with species-specific patterns. Evidence of intrachromosomal recombination between the two long terminal repeats of HERV-K(C4) is found near the huntingtin locus on chromosome 4. It is possible that members of HERV-K(C4) are involved in genetic instabilities including the RCCX modules, and in protecting the host genome from retroviral attack through an antisense strategy.

Flexion-extension rhythm in the lumbosacral spine

STUDY DESIGN AND OBJECTIVES

This study was conducted to depict the qualitative and quantitative changes of intervertebral rotation and translation from L1-L2 to L5-S1 during flexion, standing, and extension using dynamic lumbosacral radiographs.

METHODS

A radiopaque ruler was placed on the back of each subject for the normalization of translational value. Eighty-nine volunteers were examined.

RESULTS

From extension to flexion, all of the intervertebral rotations approached 0 degree from the lordotic position; the translations changed from slightly retro-listhetic to zero displacement. Using L3-L4 as a baseline for calculating the intervertebral differences in flexion, all of the rotational differences were less than 1.5 degrees, except at L5-S1, which remained 5 degrees. The mean translational difference was less than 0.6 mm, except at L5-S1, where it remained 1.5 mm.

CONCLUSIONS

The amount of total flexibility was level-dependent and its frequency distribution is important. Qualitative rhythmic changes from extension to flexion and quantitative values of intervertebral difference in flexion help define the normal flexibility more accurately.

Bilateral spontaneous pneumothoraces, pneumopericardium, pneumomediastinum, and subcutaneous emphysema: a rare presentation of paraquat intoxication

Pneumothorax, subcutaneous emphysema, and pneumomediastinum occur frequently in critically ill patients in association with blunt or penetrating injuries or other conditions while performing Valsalva-like maneuvers. We present the case of a patient with bilateral pneumothoraces, pneumomediastinum, pneumopericardium, and subcutaneous emphysema after acute paraquat intoxication.

Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes in the HLA class III region. Molecular cloning, exon-intron structure, composite retroposon, and breakpoint of gene duplication

The correlation of many HLA-associated autoimmune and genetic diseases with the polymorphic complement C4 genes may be attributed to the presence of disease susceptibility genes in the close proximity of C4. We have cloned and characterized a pair of partially duplicated genes, RP1 and RP2, located 611 base pairs upstream of the human C4A and C4B genes, respectively. The putative RP protein, consisting of 364 amino acid residues, is basic and highly hydrophilic. There is a bipartite nuclear localization signal at residues 114-131 and therefore RP may be a nuclear protein. Northern blot analysis suggested that RP is ubiquitously expressed. The 5' region of the RP1 gene is CpG rich, which is a characteristic of housekeeping genes. The RP1 gene contains nine exons. Located in the fourth intron is a cluster of Alu elements, and a newly defined composite retroposon SVA with a SINE, multiple copies of GC-rich VNTRs and an Alu element altogether enclosed by direct terminal repeats. Members of SVA are also present in the complement C2 gene located about 20 kilobases upstream of RP1 in the HLA and in the cytochrome CYP1A1 gene. Determination of the DNA sequences for RP2 from two different HLA haplotypes revealed identical hybrid sequences which resulted from fusion of RP with the tenascin-like Gene X and truncation of the 5' regions of both genes. Cumulative data suggest that the four tandemly arranged genes RP, complement C4, steroid 21-hydroxylase (CYP21), and Gene X altogether form a modular structure, RCCX. The number of RCCX modules varies from one to three or more in the population. Absence of the truncated genes RP2 and Gene XA have been detected in genomes with single RCCX modules. Duplication of the RCCX modules probably occurred before the speciation of great apes and humans as they contain the same breakpoint region of RP and Gene X gene duplication.

MR appearance of umbilical endometriosis

OBJECTIVE

We describe the MR appearance of endometriosis involving the umbilicus in two patients. One patient had a history of laparoscopy performed through the umbilicus; the other had an umbilical hernia.

MATERIALS AND METHODS

MR imaging was performed using both a body coil and a spine coil (with the patient lying prone on the spine coil). The lesions were surgically removed and their MR appearance was correlated with the results of histologic analysis.

RESULTS

The lesions were well delineated on MRI and showed evidence of prior hemorrhage consistent with endometriosis. Both lesions were shown to be endometriosis at surgical pathology.

CONCLUSION

MR imaging was useful for delineating the size and location of the lesions and excluding intraabdominal extension.

Detection of keratinocyte growth factor (KGF) transcripts from normal human and archival canine benign prostatic hyperplastic tissues

This study examined the expression of keratinocyte growth factor (KGF) gene in human and canine prostatic tissues. KGF transcript was detected in normal human prostatic tissues by reverse transcription and polymerase chain reactions (RT-PCR). PCR-generated human KGF complementary DNA (cDNA) clone was confirmed by restriction enzyme digestion analysis and partial DNA sequencing. Expression of KGF in archival canine benign prostatic hyperplastic tissues was also examined. In a pilot experiment, RNAs isolated from formalin-fixed (FF) and formalin-fixed and paraffin-embedded (FFPE) canine prostatic tissues were shown to be of sufficient quality to permit amplification of KGF mRNA by RT-PCR. The transcript of a housekeeping gene, glucose-6-phosphate dehydrogenase (G6PD), was detected by RT-PCR indicating the quality of RNAs to be more than adequate for RNA expression analysis. Later, total RNA from two archival canine FF prostate tissue types, benign prostatic hyperplasis and mild glandular hyperplasia, were used to amplify canine KGF transcripts. Southern hybridization analysis using rat and human KGF cDNAs as probes confirmed the fidelity of the amplified PCR product and it was indeed canine KGF.

Effects of splenectomy, devascularization and esophageal transection on portal venous pressure and portal perfusion in cirrhotic patients with bleeding esophageal varices

This investigation sought to determine the effects of splenectomy, devascularization and esophageal transection on portal venous pressure and portal perfusion in cirrhotic patients with a previous history of hemorrhage from esophageal varices. From June 1988 to June 1991, 54 patients with liver cirrhosis underwent this nonshunting procedure for esophageal varices. Of these patients, 24 patients (20 men and four women, 39 to 68 years of age, all in Child's class A) were examined for portal pressure before, during and after the nonshunting operations. Portal venous perfusion was assessed from the venous phase of the superior mesenteric arteriogram preoperatively and one year after surgery in 16 of these 24 patients. There was no significant change (p > 0.05) in cardiac output and systemic blood pressure after the operation. The portal venous pressure before surgery was 28.4 +/- 8.0 mmHg with a range from 18 to 44 mmHg. A statistically significant decrease (p < 0.05) in the portal pressure was observed after ligation of the splenic artery (26.6 +/- 8.9 mmHg), splenectomy (24.8 +/- 8.0 mmHg), and devascularization with transection (23.4 +/- 7.5 mmHg). No correlation between the portal pressure change and splenic weight was noted (p > 0.05). Postoperative portal perfusion remained the same or even improved in 15 of these 16 patients. Only in one patient was the portal perfusion worse after the operation; this patient developed encephalopathy about 18 months later. In conclusion, a significant reduction in portal pressure is noted after nonshunting procedures but a persistent, relatively high portal pressure is maintained. Good postoperative portal perfusion can also be maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Lumbosacral kinematics in the sagittal plane: a radiographic study in vivo

Lateral functional radiographs of flexion and extension using Putto's method were examined in 89 normal subjects. A specially-designed radiopaque ruler was placed on each film for calibration. A computer-assisted method was used for digitization and analysis. There were weak negative correlations between age and range of motion, especially at the L4-L5 level (r = 0.437). No significant correlation was noted between age and translation. For flexion-extension rotation, although large variations may limit its usefulness in judging instability in some clinical settings, the data still provide a good diagnostic basis. For translation changes, 2 mm is regarded as acceptable in most cases at levels from L1 to L5, but not at the level of L5-S1 where the average translation change was only 0.4 mm. The differences in the absolute translation value among different positions were not statistically significant (p = 0.064).

Transcriptional activation of human zeta 2 globin promoter by the alpha globin regulatory element (HS-40): functional role of specific nuclear factor-DNA complexes

We studied the functional interaction between human embryonic zeta 2 globin promoter and the alpha globin regulatory element (HS-40) located 40 kb upstream of the zeta 2 globin gene. It was shown by transient expression assay that HS-40 behaved as an authentic enhancer for high-level zeta 2 globin promoter activity in K562 cells, an erythroid cell line of embryonic and/or fetal origin. Although sequences located between -559 and -88 of the zeta 2 globin gene were dispensable for its expression on enhancerless plasmids, they were required for the HS-40 enhancer-mediated activity of the zeta 2 globin promoter. Site-directed mutagenesis demonstrated that this HS-40 enhancer-zeta 2 globin promoter interaction is mediated by the two GATA-1 factor binding motifs located at -230 and -104, respectively. The functional domains of HS-40 were also mapped. Bal 31 deletion mapping data suggested that one GATA-1 motif, one GT motif, and two NF-E2/AP1 motifs together formed the functional core of HS-40 in the erythroid-specific activation of the zeta 2 globin promoter. Site-directed mutagenesis further demonstrated that the enhancer function of one of the two NF-E2/AP1 motifs of HS-40 is mediated through its binding to NF-E2 but not AP1 transcription factor. Finally, we did genomic footprinting of the HS-40 enhancer region in K562 cells, adult nucleated erythroblasts, and different nonerythroid cells. All sequence motifs within the functional core of HS-40, as mapped by transient expression analysis, appeared to bind a nuclear factor(s) in living K562 cells but not in nonerythroid cells. On the other hand, only one of the apparently nonfunctional sequence motifs was bound with factors in vivo. In comparison to K562, nucleated erythroblasts from adult human bone marrow exhibited a similar but nonidentical pattern of nuclear factor binding in vivo at the HS-40 region. These data suggest that transcriptional activation of human embryonic zeta 2 globin gene and the fetal/adult alpha globin genes is mediated by erythroid cell-specific and developmental stage-specific nuclear factor-DNA complexes which form at the enhancer (HS-40) and the globin promoters.

The effects of putaminal hemorrhage upon motoneuron excitability

To evaluate the putaminal influence on spinal motoneuron excitability, H-reflex recovery curve (HRRC) was studied in 24 patients with putaminal hemorrhage. Thirteen patients had increased facilitation, most significantly between 150 msec and 300 msec after the conditioning stimulus. It is proposed that putaminal dysfunction may cause an impairment in inhibition of soleus motoneuron excitability. Such a putaminal disinhibition is probably related to a disturbance of the thalamo-striatal and thalamic fasciculus circuits.

Emergency endoscopic nasobiliary drainage for acute calculous suppurative cholangitis and its potential use in chemical dissolution

Acute suppurative cholangitis is one of the common causes of acute abdomen in Taiwan. Emergency decompression is a life-saving procedure if patients fail to respond to antibiotic treatment. From July 1988 to June 1991, 224 patients were encountered with concomitant bile duct stones and cholangitis; 40 were brought to the emergency service with shock or mental confusion or responded poorly to antibiotic treatment. The patients consisted of 20 males and 20 females aged 21-81 years (mean age 64 years); 55% had intrahepatic duct stones, 50% had positive blood culture, 38% had undergone previous biliary surgery, 25% had concomitant medical illnesses and 20% presented with mental confusion. Emergent endoscopic nasobiliary drainage (ENBD) was performed within 48 h of each patient's arrival in the emergency room. In 3 days all the patients exhibited significant improvement as defined by body temperature, vital signs, white blood cell count, serum bilirubin and alkaline phosphates levels. When their condition had stabilized, 21 patients underwent elective surgery. Six patients received ethylenediaminetetraacetic acid infusion through an ENBD tube. Two of the patients' stones dissolved completely. Six patients received papillotomy with stone removal. The remaining patients refused further treatment. There was no hospital mortality. It is therefore concluded that ENBD offers an effective treatment for acute calculus suppurative cholangitis and it is a potential route of administration for the chemical dissolution of bile duct stones.

Cytotoxicity studies on some novel 2,6-dimethoxyhydroquinone derivatives

Six synthetic 2,6-dimethoxyhydroquinone derivatives were shown to have different degrees of cytotoxicity to two human tumor cell lines (KB and PC-9) under the synergistic activation of L-ascorbic acid. Two representative compounds displayed very low time-schedule-independent index, showing that the cytotoxic action is independent of time of drug treatment. The addition of catalase produced a significant inhibitory effect on the cytotoxicity of two representative compounds, indicating that the cytotoxic action is mediated by the generation of H2O2, which may yield hydroxyl radicals via various mechanisms. ESR studies employing the spin-trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that massive hydroxyl radicals were generated from four of these drugs as a non-linear function of L-ascorbic acid concentration. The results indicate the possible involvement of hydroxyl radicals in the cytotoxic action of these novel drugs.

Use of hematoma size on computerized tomography and calculated average bleeding rate as indications for immediate surgical intervention in blunt renal trauma

One of the most demanding situations for a urologist is to decide which blunt renal trauma patients need immediate surgical exploration. Although computerized tomography can offer a lot of invaluable information, clear guidelines for selection of surgical versus conservative treatment are still lacking. A retrospective study of 15 blunt renal trauma cases showed that the hematoma size measured from computerized tomography using the method of summation planimetry bears a much closer correlation with the clinical outcome of the patient than does the degree of kidney parenchymal defect. Moreover, the average bleeding rate, calculated by dividing the size of the hematoma by the time elapsed from injury to scanning, gives a more accurate prediction for the need for immediate surgical treatment.

Lumbar lordosis: normal adults

Lumbar curvatures in 149 normal adults from the general population were studied. There were 76 men and 73 women with an average age of 50 years. The mean values of lumbar lordotic angle (LLA), lumbosacral angle (LSA) and sacral inclination angle (SIA) were 33.2 +/- 12.1 degrees, 11.4 +/- 4.7 degrees and 26.4 +/- 10 degrees, respectively. A high correlation was noted between LLA and SIA (r = 0.883, p = 0.0001). LLA is an ideal parameter for the evaluation of lumbar lordosis. The normal value of LLA can be defined as 20-45 degrees with a range of 1 SD. No significant differences were noted in these three angles between males and females in any age group (LLA, p = 0.647; LSA, p = 0.80; SLA, p = 0.189). Also, X-ray findings indicated there were no significant differences between these three angles in spondylotic spines and those spines with a normal appearance from X-ray finding. The average LLA increased with age. Significant lumbar lordotic angle differences were noted between those patients less than 35 years of age and those greater than 60 years, as well as in the 35-60 age group and the greater than 60 age group (p = 0.0056).

Pancreas divisum with early pancreatic cancer--presenting as chronic obstructive pancreatitis

A 61-year-old man experienced four bouts of pancreatitis in 1 year. Detailed history taking and a series of examinations, including sonography, computed tomography scan, and endoscopic retrograde cholangiopancreatography (ERCP), revealed pancreas divisum on the first admission. He was treated conservatively. However, repeated ERCP on the fourth admission, 1 year later, showed a small filling defect in the tail of the pancreatic duct. A distal pancreatectomy was carried out. Pathological studies revealed a small papillary adenocarcinoma (1.5 x 1.0 x 0.5 cm) confined to the pancreatic duct grossly with minimal parenchymal invasion microscopically. He has been free from cancer and pancreatitis for 13 months since the operation.

The CACC box upstream of human embryonic epsilon globin gene binds Sp1 and is a functional promoter element in vitro and in vivo

DNA sequences 179 base pairs upstream and 23 base pairs downstream of the cap site of human embryonic epsilon globin gene exhibit promoter activity in transfected cell cultures. The nuclear factor binding in vitro of this epsilon promoter region was studied by DNase I foot-printing, methylation interference, and gel mobility shift assay. Four major nuclear factor-binding sites are detected in complexes formed with unfractionated nuclear extracts: NF-E1 at -163, epsilon F1 at -143, CACC box at -111, and CBF at -81, respectively. Of these, NF-E1 is an erythroid-specific factor. epsilon F1 is probably a ubiquitous factor because it is present in both erythroid K562 cells and nonerythroid HeLa cells. The epsilon F1-binding site exhibits sequence similarity to that of the cAMP response element-binding protein family of transcription factors. Finally, the CCAAT box-binding protein (CBF)-binding site centers around the CCAAT promoter box. Comparative binding studies with unfractionated nuclear extracts and affinity purified HeLa Sp1 demonstrated that the epsilon-globin CACC box at -111 is a binding site of Sp1. The spatial arrangements of the NF-E1-binding site, the CACC box, and CCAAT box, with respect to their mutual separations by approximately integral numbers of helical turns, is well conserved in all mammalian embryonic epsilon globin promoters. Transient expression assay, using human growth hormone gene as the receptor, demonstrated that similar to the other two human beta-like globin genes (beta and gamma), the CACC box of epsilon globin gene is an essential promoter element for epsilon globin gene expression in vivo in K562 cells. This CACC promoter box also functions in vitro in nuclear extracts prepared from K562 cells. These data, together with Sp1-binding studies of the human beta and gamma globin CACC boxes, suggest that the general transcription factor Sp1, through its differential interactions with different forms of CACC promoter boxes, is an essential component of the machinery that controls the developmental program of mammalian globin gene regulation.

[Quantification of acetabular coverage in normal adult]

Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

The complete exon-intron structure of a human complement component C4A gene. DNA sequences, polymorphism, and linkage to the 21-hydroxylase gene

The human complement component C4A and C4B genes are located within the class III region of the MHC. The polymorphic C4 genes are highly complex including variations in class (isotype), size, and number of genes. The DNA sequence for a C4A gene has been determined, except for a large intron of 6 to 7 kb long. The C4A gene consists of 41 exons encoding a transcript for a precursor protein of 1744 amino acid residues. Several structural and functional aspects of C4 have been located to individual exons. The active site of the anaphylatoxin C4a matches to a splice junction. Some unique properties of C4, such as, the alpha-gamma-chain junction, the tyrosine sulfation sites, and the post-secretory metalloprotease cleavage site, are encoded by a single exon. Comparison of human C4 with published data for mouse C4, human C3 and rat alpha 2 macroglobulin genes revealed that these evolutionary-related genes share very similar exon-intron structures. Altogether 20 polymorphic sites in human C4 have been detected by various techniques. Presumably, these polymorphic residues account for the functional, structural, and serologic variations observed among the various allotypes. A PvuII restriction length polymorphism has been detected within the region of DNA coding for C4a. The intergenic region between C4 and the neighboring 21-hydroxylase gene, CYP21, is approximately 3028 bp in size.

The complete exon-intron structure of a human complement component C4A gene. DNA sequences, polymorphism, and linkage to the 21-hydroxylase gene

The human complement component C4A and C4B genes are located within the class III region of the MHC. The polymorphic C4 genes are highly complex including variations in class (isotype), size, and number of genes. The DNA sequence for a C4A gene has been determined, except for a large intron of 6 to 7 kb long. The C4A gene consists of 41 exons encoding a transcript for a precursor protein of 1744 amino acid residues. Several structural and functional aspects of C4 have been located to individual exons. The active site of the anaphylatoxin C4a matches to a splice junction. Some unique properties of C4, such as, the alpha-gamma-chain junction, the tyrosine sulfation sites, and the post-secretory metalloprotease cleavage site, are encoded by a single exon. Comparison of human C4 with published data for mouse C4, human C3 and rat alpha 2 macroglobulin genes revealed that these evolutionary-related genes share very similar exon-intron structures. Altogether 20 polymorphic sites in human C4 have been detected by various techniques. Presumably, these polymorphic residues account for the functional, structural, and serologic variations observed among the various allotypes. A PvuII restriction length polymorphism has been detected within the region of DNA coding for C4a. The intergenic region between C4 and the neighboring 21-hydroxylase gene, CYP21, is approximately 3028 bp in size.

Inflammatory pseudotumor of the liver with occlusive endophlebitis: report of a case

Inflammatory pseudotumor (IPT) of the liver is an extremely rare benign tumor. Only 12 cases have so far been reported in the English literature. The etiology and pathogenesis of IPT remain obscure. We herein present an additional case of IPT of the liver with occlusive endophlebitis in a 36-year-old female. Immunohistochemical studies demonstrated the polyclonal nature of the plasma cells in the tumor, including IgA, IgM, IgG, kappa and lambda. The inflammatory pseudotumor should be kept in mind in the differential diagnosis of hepatic space-occupying malignant lesions.

[Effect of electroshock on learning-dependent long-term potentiation in rat hippocampal CA3 area]

Population spikes were recorded from hippocampal CA3 of freely moving rats following stimulation of the perforant path. Six rats were trained to perform conditioned drinking behavior. (1) Animals were treated with electroshock in less than 15 minutes after daily training session for a period of 6 consecutive days. Synaptic efficacy did not increase and the conditioned response could not be established during the behavioral training in four rats, synaptic efficacy was increased, the long-term potentiation (LTP) appeared and the conditioned behavior was established in other two rats. (2) After consolidation of conditioned behavior, electroshock temporarily caused suppression of the learning-dependent LTP and the correlative conditioned response. Both LTP and the correlative conditioned response recovered in one to four hours after electroshock. In these cases, the maximal development of LTP preceded the development of conditioned behavior. The results indicated that the learning-dependent LTP might be one of the neural substrates underlying learning and memory.

Characterization of two hybrid C4 allotypes (C4A*12 and C4B*3) by electrophoretic, serological and restriction fragment length polymorphism analyses

Informative pedigree analysis of two rare C4 allotypes is reported. One proband was C4A deficient as a consequence of having one haplotype with a deleted C4A gene, and the second haplotype with two C4B genes--one encoding the common C4B*1 and one encoding a unique hybrid gene product C4B*3. C4B*3 had approximately normal C4B hemolytic activity, a single alpha-chain of MR 94,000 by SDS-PAGE but was positive for Rg:1,2 by hemagglutination inhibition (HAI) and for Rg:1 by Western blotting. The hybrid nature was confirmed by RFLP analysis with a Rg:1-associated fragment by Eco0109 digestion but no C4A-associated fragments by N1aIV digestion were identified. A gene conversion at Locus I which included just the C4 isotype region could explain the structure of C4B*3. The second pedigree had a Rodgers negative C4A*12 allotype. This C4A gene, which segregated with a single 7.0 kb TaqI fragment, encoded a C4A alpha-chain, which was negative for Rg:1 epitope. The affected haplotype lacked the Rg:1-associated fragment by Eco0109 digestion yet had the C4A specific N1aIV digestion fragment. These studies successfully employed RFLP analyses to confirm serologic and electrophoretic observations.

A physical map linking the five CD1 human thymocyte differentiation antigen genes

Human CD1 is a family of thymocyte differentiation antigens which consist of heavy chains with mol. wts between 43 and 49 kd binding to beta 2 microglobulin. They are distant relatives of the major histocompatibility complex (MHC) class I and II products. Five human CD1 genes have been described. Three (CD1A, -B and -C) code for the serologically defined CD1a, -b and -c antigens. The protein products of the other two genes, CD1D and CD1E, remain unknown. All CD1 genes are located on chromosome 1 and hence are independent of the MHC locus. In this paper, the tight linkage of the CD1 genes has been established by pulse field gel electrophoresis, cosmid cloning and walking techniques. The 190 kb of DNA linking all five CD1 genes has been spanned by 14 overlapping cosmids. The order of the genes in the CD1 complex is CD1D-CD1A-CD1C-CD1B-CD1E, and, with the exception of CD1B, they are arranged in the same transcriptional orientation. The genes are evenly spaced in the complex except for the distance between CD1D and CD1A, which is two to three times greater than the average.

The rabbit CD1 and the evolutionary conservation of the CD1 gene family

A comparison of the genes encoding the CD1 leucocyte differentiation antigens in man and mouse shows important differences which prompted us to analyze the CD1 genes of the rabbit. We have found that the rabbit genome contains multiple CD1 loci. Upon cloning and sequencing, one of these loci was found to encode the known rabbit CD1-like antigen (R-Ta) and to be closely related to the human CD1b gene, which is absent in the mouse, while a second rabbit gene is closely related to both the human R3 and the mouse CD1 genes. The data reinforce the notion of the existence of two classes of CD1 genes, one of which is conserved in all species, while the other, albeit also evolutionarily old, has been deleted in mice as well as in other rodents.

Unique sequence organization and erythroid cell-specific nuclear factor-binding of mammalian theta 1 globin promoters

The theta 1 globin gene is an alpha globin-like gene, and started to diverge from the other members of the alpha globin family 260 million years ago. DNA sequencing and transcriptional analysis indicated that it is functional in erythroid cells of the higher primates, but not in prosimians and rabbit. The theta 1 promoter region of higher primates including man consists of GC-rich sequences characteristic of housekeeping gene promoters, and CCAAT and TATA boxes located further upstream. It is shown here that the housekeeping gene promoter-like region of human theta 1 contains two tandemly arranged, GC-rich motifs (GC-I and GC-II). Of these, GC-II interacts with nuclear factor(s) present in the globin-expressing, erythroleukemia cell line K562, before and after hemin induction. GC-I, however, interacts with nuclear factor(s) only present in hemin-induced K562 cells. These factors are different from previously reported erythroid cell-specific factors, and are not detectable in non-erythroid Hela cells. Furthermore, the sequence of the motif GC-I and its location relative to ATG codon have been conserved among all known mammalian theta 1 globin genes. Finally, and most interestingly, the CCAAT box of theta 1 is contained within a 38 bp internal segment of Alu repeat sequence. Immediately upstream from this CCAAT box-containing Alu repeat segment is a 241 bp Alu repeat pointing in the opposite direction. The conservation of this novel arrangement among the higher primates suggests that an inserted Alu family repeat and its flanking genomic sequence have co-evolved, for at least 30 million years, to provide the canonical CCAAT and TATA promoter elements of the theta 1 globin genes in higher primates.

Evaluation of a new work seat for industrial sewing operations: results of three field studies

A newly developed work seat for industrial sewing operations was compared with a traditional sewing work seat to evaluate the effectiveness of design features. The new seat was designed with special seat-pan and backrest features to accommodate the musculoskeletal geometry of a low sit-stand posture. The seat-pan consisted of a pelvic support which supported the ischial tuberosities and areas behind them, and a thigh support which maintained the thighs at a 15 degrees downward angle, resulting in a 105 degrees trunk-thigh angle. The backrest consisted of a lumbar support which preserved lumbar lordosis and a thoracic support which supported the upper back during backward leaning. The traditional work seat was similar to an office chair (i e, a large horizontal seat-pan and a wide backrest) with the exception of having a higher than normal seat-height. This investigation consisted of three studies to compare the seats: (1) A user comfort and acceptance experiment which compared the initial psychophysical responses of 50 industrial sewers when introduced to the new seat; (2) a backrest usage experiment which compared the duration of backrest use among 10 industrial sewers; and (3) a follow-up experiment to evaluate chair preference after extended use of the new seat. The results of the user comfort and acceptance experiment found that the new work seat had greater comfort and user preference; the results of the backrest usage experiment found that the new seat had greater backrest use than the traditional seat; the results of the follow-up experiment found that the preference for the new seat was maintained over time and not due to a Hawthorne Effect.

MR imaging of cavernous sinus involvement by pituitary adenomas

The ability of high-resolution MR imaging (1.5 T) to detect invasion of the cavernous sinuses by pituitary adenoma was determined through a retrospective review of 74 patients. These patients were divided into three groups: 25 normal subjects, 24 subjects with invasive pituitary adenomas, and 25 subjects with noninvasive pituitary adenomas. A fourth group of 30 patients, who subsequently underwent surgery for pituitary adenoma, was evaluated prospectively by MR for the presence or absence of cavernous sinus invasion. Several features were analyzed: (1) the detectability of the medial and lateral dural margins of the cavernous sinus (2) the size and variation in intensity of compartments within the cavernous sinus (3) the relationship of endocrine function to the surgical and MR appearance of the cavernous sinus and (4) carotid artery displacement or encasement by tumor. The normal cavernous sinuses were usually symmetric, but their sizes varied. The lateral dural margin of the cavernous sinus was always recognized on MR as a linear, discrete, low-intensity area. The medial dural margin (pituitary capsule) was seen on MR in only two of the 25 normal patients. In all 24 patients with cavernous sinus invasion involvement was unilateral and was most common with laterally positioned prolactin or adrenocorticotropic hormone secretory adenomas. Invasion of the cavernous sinus was suspected by MR in only two of the 13 invasive microadenomas and was questionable in three. In 10 of the 11 macroadenomas with surgically proved dural invasion, MR demonstrated an asymmetric increase in size and intensity of the superior and inferior cavernous sinus compartments. Noninvasive macroadenomas compressed and displaced the cavernous sinus bilaterally. The prospective MR evaluation of 30 patients undergoing surgery for pituitary tumor revealed a sensitivity for predicting cavernous sinus invasion of 55%, a specificity of 85.7%, a positive predictive value of 62.5%, and a negative predictive value of 81.8%. No feature permitted certain distinction between invasive and noninvasive microadenomas, as the medial dural wall of the cavernous sinus could not be reliably identified. The most specific sign of cavernous sinus invasion was carotid artery encasement.

Reduction of common carotid resistance upon stimulation of an area dorsal to the facial nucleus of cats

In chloralose-urethane-anesthetized cats, electrical stimulation and glutamate injection on a small reticular area just dorsal to the facial nucleus (DFA) elicited an ipsilateral reduction in the common carotid resistance (CCR-reduction) with no or minimal change in other cardiovascular parameters. CCR-reduction was mediated via facial and glossopharyngeal nerves, involving partially muscarinic and partially non-muscarinic mechanisms.

Molecular characterization of the HLA-linked steroid 21-hydroxylase B gene from an individual with congenital adrenal hyperplasia

21-Hydroxylase deficiency which causes congenital adrenal hyperplasia is one of the most common defects of adrenal steroidogenesis. There are two 21-hydroxylase genes in man, A and B, and these have been mapped to the HLA class III region. Only the 21-hydroxylase B gene is thought to be active. To understand the molecular basis of congenital adrenal hyperplasia in a patient with the salt-wasting form of the disease, we cloned and characterized his single 21-hydroxylase B gene. The nucleotide sequence of this gene and a 21-hydroxylase B gene from a normal individual have been determined. Comparison of the two sequences has revealed 11 nucleotide alterations, of which two are in the 5' flanking region, four are in introns, one is in the 3' untranslated region and four are in exons. Two of the differences in exons cause codon changes, with Ser-269 and Asn-494 in the normal 21-hydroxylase B gene being converted to Thr and Ser, respectively. These amino acid substitutions may give an insight into those residues necessary for 21-hydroxylase enzymatic activity. We have also confirmed that the 21-hydroxylase A gene is a pseudogene due to three deleterious mutations in the exons. In addition, comparison of the 21-hydroxylase B gene sequence with other published sequences indicates that this microsomal cytochrome P-450 may be polymorphic.

Definitive RFLPs to distinguish between the human complement C4A/C4B isotypes and the major Rodgers/Chido determinants: application to the study of C4 null alleles

Definitive restriction fragment length polymorphisms (RFLPs) representing the exact locations responsible for isotypicity between the human complement components C4A and C4B, and their generally associated major Rodgers (Rg1) and Chido (Ch1) antigenic determinants, have been designed. By means of C4d-specific genomic probe for Southern blot analysis, a C4A gene can be defined by the presence of the 276 bp and 191 bp N1a IV fragments, while a C4B gene can be defined by a single 467 bp N1aIV fragment. In addition, an Rg1-expressing C4 gene can be represented by a 565 bp EcoO 109 fragment, and a Ch1-expressing C4 gene by a 458 bp EcoO 109 fragment, under the same conditions. All these polymorphic restriction fragments can be unambiguously and conveniently detected. In combination with the Taq I polymorphic patterns specific for the C4 loci and for the neighboring 21-hydroxylase genes, the nature and structure of the tandem C4,21-hydroxylase gene complex can be elucidated. In this study, it is inferred that the null allele of the HLA haplotype B44 DR6 C4A3 C4BQO is not a C4B allele, but probably encodes another C4A 3 allotype at the second C4 locus.

Structural basis of the polymorphism of human complement components C4A and C4B: gene size, reactivity and antigenicity

The human complement components C4A and C4B are highly homologous proteins, but they show markedly different, class-specific, chemical reactivities. They also differ serologically in that C4A generally expresses the Rodgers (Rg) blood group antigens while C4B generally expresses the Chido (Ch) blood group antigens. C4A 1 and C4B 5 are exceptional variants which possess their class-specific chemical reactivities, but express essentially the reversed antigenicities. The genes encoding the typical Rg-positive C4A 3a and Ch-positive C4B 3 allotypes and the interesting variants C4A 1 and C4B 5 have been cloned. Characterization of the cloned DNA has revealed that the genes encoding the A 3a, A 1 and B 3 allotypes are 22 kb long, but that encoding B 5 is only 16 kb long. Comparison of derived amino acid sequences of the polymorphic C4d fragment has shown that C4A and C4B can be defined by only four isotypic amino acid differences at position 1101-1106. Over this region C4A has the sequence PCPVLD while C4B has the sequence LSPVIH, and this presumably is the cause of their different chemical reactivities. Moreover, the probable locations of the two Rg and the six Ch antigenic determinants have been deduced. Our structural data on the C4A and C4B polymorphism pattern suggests a gene conversion-like mechanism is operating in mixing the generally discrete serological phenotypes between C4A and C4B.

Improved methods of direct and cultured chromosome preparations from chorionic villous samples

A new method is described for preparing direct mitotic chromosome spreads from chorionic villous samples, which has resulted in sufficiently high yields of well-banded metaphases to permit a complete standard chromosomal diagnosis in 20 of 20 cases. A method of establishing monolayer cultures from this material that can be harvested from 3 to 7 days after initiation is also presented.

Expression of T4 early genes 62, 44, 45 and 46 in the lambda-T4 recombinant phage lambda 806-17

A lambda-T4 recombinant phage, lambda 806-17, which carries the T4 early genes 62, 44, 45 and 46, was studied inside a homoimmune lysogen. Under such conditions, gene expression from the lambda promoters is represented. Results showed extensive expression of gene 46, and significant expression of genes 62 and 45. The expression of these early T4 genes is presumed to depend on T4 promoters included in the cloned fragment. A new promoter proximal to gene 46 is implicated. The results also indicate that the extent of gene expression, in terms of complementation, increases with the time allowed for expression.

Polymorphism of human complement component C4

An assessment has been made of the polymorphism of human complement component C4 by comparing derived amino acid sequences of cDNA and genomic DNA with limited amino acid sequences. In all, one complete and six partial sequences have been obtained from material from three individuals and include two C4A and two C4B alleles. Differences were found between the 4 alleles from 2 loci in only 15 of the 1722 amino acid residues, and 12 lie within one section of 230 residues, which in 1 allele also contains a 3-residue deletion. In three variable positions, an allelic difference in one C4 type was common to the other types. Three nucleotide differences were found in four introns. In spite of marked differences in their chemical reactivity, the many allelic forms appear to differ in less than 1% of their amino acid residue positions. This unusual pattern of polymorphism may be due to recent duplication of the C4 gene, or may have arisen by selection as a result of the biological role of C4, which interacts in the complement sequence with nine other proteins necessitating conservation of much of the surface structure.

Mosaic autosomal trisomy in cultures from spontaneous abortions

In a consecutive series of 592 karyotyped spontaneous abortions, ten of 103 autosomal trisomies were mosaic, with a normal cell line also present. The frequency of mosaicism (10%) is much higher than that reported in Down syndrome, but similar to that reported in amniotic fluid cultures and in induced abortions. The most likely explanations for this discrepancy are (1) previous underestimation of mosaicism in live births or (2) mosaicism which is often restricted to extraembryonic fetal tissue.

Supernumerary small chromosomal anomaly: report of three cases including one with a familial inversion of chromosome 5

Three cases of a small supernumerary chromosomal anomaly of essentially unknown origin associated with wide variability of clinical expression are reported. Case II has, in addition, a pericentric inversion of chromosome 5, which enables us to propose a mechanism, involving an unsuccessful crossing over, for the origin of the supernumerary chromosome.