Fluorescence polarization--a new tool for cell and molecular biology

Fluorescence polarization (FP) equilibrium binding assays differ from other types of binding studies in one important regard: they require no steps to separate free from bound tracer and are therefore fast, simple and accurate.

Patterns of genetic variability at individual minisatellite loci in minke whale Balaenoptera acutorostrata populations from three different oceans

The genetic variability at six cloned minisatellite loci was analyzed in minke whale populations from the North Atlantic, North Pacific, and Antarctic Oceans. Three loci displayed only a few different alleles in each of the three populations, with heterozygosity ranging from 0.00 to 0.47, and three loci revealed many different alleles in at least two fo the three populations, with heterozygosity ranging up to 0.98. Using small sample sizes, samples from two adjacent Antarctic Management Areas were not found to differ significantly in allele frequencies at any of the six loci. The use of principal coordinate analysis to detect multilocus disequilibria was explored. No significant evidence was found of intrapopulation heterogeneity within the pooled Antarctic sample. Pronounced interoceanic differences were observed at every locus, confirming the existence of genetic isolation found earlier using more conventional marker systems. The populations from the three oceans appear to have diverged to such a degree that the hypervariable loci have had time to evolve independently and arrive at different evolutionary stages in different populations. The frequency of undetected "null" alleles is remarkably high in minke whale populations compared to human populations and is probably a result of the cloning protocol used. Minisatellite loci are shown to provide a powerful population genetic tool, supplying levels of resolution appropriate to different degrees of evolutionary divergence.

Histologic characterization of uterine papillary serous adenocarcinoma

Uterine papillary serous adenocarcinoma (UPSC) is one of the most aggressive endometrial tumors. UPSC has been associated with an increased propensity for extrauterine spread. Survival rates of not more than 50% are commonly reported even for tumors which appear to be confined to the uterus. Small areas of UPSC can be found in otherwise well-differentiated endometrial lesions and yet still determine the overall prognosis. In the present study we evaluated histologic criteria that might be helpful in diagnosing small-volume UPSC, including silver-stained nucleolar organizer regions (AgNOR) which have prognostic importance in a variety of tumors, and nuclear size which has been used for prognostication in endometrial cancer. We examined 25 UPSC specimens and compared them to grade III (GIII, n = 10) and grade I (GI, n = 10) typical endometrial adenocarcinoma using the following parameters: mean AgNOR count per cell was UPSC 6, GIII 6.0, and GI 4.3; mean AgNOR area was UPSC 1.28 microns2, GIII 1.35 microns2, and GI 0.86 microns2; total AgNOR area per cell was UPSC 7.5 microns2, GIII 8.13 microns2, GI 4.47 microns2; and nuclear size was UPSC 66.9 microns2, GIII 60.3 microns2, GI 34.8 microns2. All differences between UPSC or GIII tumors and GI lesions were statistically significant. Overexpression of p53, as determined histochemically, was seen in 64% of the UPSC specimens. UPSC is characterized by high AgNOR count and area per cell, large nuclear size, and a high rate of p53 overexpression. Evaluation of these parameters in biopsy material may aid in selecting high-risk patients for adjuvant therapy trials.

Minisatellite DNA markers in the chicken genome. II. Isolation and characterization of minisatellite loci

The isolation of chicken minisatellites is reported. Two charomid libraries were constructed from fractions of size-selected MboI-digested genomic DNA. A total of 5985 colonies were screened with the multilocus probes 33.6 and 33.15; 137 positives were obtained (2.35%). A total of 55 clones were tested against four unrelated chickens; 30 revealed variable single locus patterns. More detailed characterization was made of 15 probes, which were tested against four families comprising a total of 53 offspring. Of parent/offspring comparisons 51% were informative for segregation. No mutations were detected. Three minisatellites were linked on the same autosome, implying that these loci may occur in clusters, and one was Z chromosome-linked. Heterozygosity and allelic variability were measured in 67 individuals from several different strains and breeds. Mean heterozygosity ranged from 50 to 84%. Minisatellite loci appear to be highly variable in the chicken and should provide highly informative markers in intraspecific crosses in genome mapping studies.

Perceptions of denture aesthetics: a two-centre study of denture wearers and denture providers

A study into perceptions of complete dentures was carried out in two dental schools, one in Australia and the other in England. Two-hundred participants were asked to assess photographs of five sets of dentures for age, gender and personality. Results were subjected to a multi-rater kappa statistic. Although no centre was determined to be better than the other, it was highly significant that Australian teachers were confident enough to state that they were unable to determine age or gender from the information supplied.

Minisatellite DNA markers in the chicken genome. I. Distribution and abundance of minisatellites in multilocus DNA fingerprints

This paper reports the detailed characterization of multilocus minisatellite DNA fingerprints in the chicken. Results are presented of DNA fingerprint segregation analyses carried out in three chicken pedigrees, calculating the number of detected loci, testing for Mendelian inheritance, and cosegregation among fingerprint bands. Two pedigrees (families 1 and 2) were analysed using the Jeffreys probes 33.6 and 33.15 only, and one pedigree (family 3) was analysed using 33.6, 33.15, 3' alpha-globin HVR and M13 protein III gene repeat. Mean band transmission frequencies in families 1 and 2 were near to the Mendelian expectation of 0.5 and no mutations were observed. Family 3 showed transmission frequencies slightly exceeding 0.5. Linkage among bands was higher than observed in some other avian species, with each allele represented by a mean of 1.48 HaeIII fragments. Cosegregation of heterozygous parental fragments representing distinguishable loci followed the expected binomial distribution. The number of minisatellites detectable by the four probes was estimated to be 217. The pattern of cosegregation among those minisatellite loci was tested against that expected for different levels of recombination through the use of a simulation model. We conclude that most minisatellites are unlinked and probably widely dispersed in the chicken genome.

An experimental study of reflex variability in selective dorsal rhizotomy

Significant problems regarding the measurement technique currently used to choose nerve roots for sectioning in the selective dorsal rhizotomy procedure have recently been reported. To better understand the source of these problems, a series of six experiments was performed in which the selective rhizotomy technique was applied to cats that were either intact, decerebrate, or spinalized. Measurements were made before and after partial rhizotomy. In decerebrate preparations, large, spontaneous changes in reflex threshold were observed over short periods of time, especially after partial rhizotomy was performed, and threshold changes greater than 1000% could be observed over 10-minute periods. Using constant-current stimulation of the dorsal root at threshold, the response of each ipsilateral leg muscle demonstrated frequent changes, and changes coincided with the variability in threshold estimation. In addition, very low thresholds were measured (0.1 to 0.25 mA) in half (3 of 6) of these experiments, these measurements being well below the currents customarily used for intraoperative decision making. Stimulation at twice threshold was found to consistently increase the pathological quality of the responses observed. Although intact animals never displayed contralateral responses when stimulated at threshold, such contralateral responses could readily be elicited at twice threshold. These laboratory results raise further doubts regarding the reliability of the measurement techniques now widely used for selective dorsal rhizotomy.

Comparative analysis of intra- and interpopulation genetic diversity in Bufo bufo, using allozyme, single-locus microsatellite, minisatellite, and multilocus minisatellite data

Estimates of genetic diversity within, and of variation among, semi-isolated populations of the common toad (Bufo bufo) were derived and compared across four classes of nuclear genetic markers, including allozymes, microsatellites, and single and multilocus minisatellites. Estimates of multilocus heterozygosity and the number of alleles per locus derived from allozymes were lower than for each class of variable number of tandem repeat (VNTR) markers. The degree of interpopulation genetic divergence as determined by genetic distance was generally concordant across all markers, although interpopulation variance in allozyme allele frequency (as measure by F-statistics) was greater than that documented for each VNTR locus. For both classes of VNTR loci, migration appeared to have less influence than mutation on the extent of interpopulation divergence. Analyses suggest that singly and multiply detected VNTR loci may be highly informative for population-level analyses addressing questions concerning population subdivision and breeding structure.

SPOT: an improved differential screening protocol that allows the detection of marginally induced mRNAs

We have developed a differential screening technique, single plate one transfer (SPOT), that allows the easy detection of mRNAs induced only 2-fold to 3-fold or less above background. As a model system, we looked at the induction of mRNA by parathyroid hormone (PTH) in ROS 17/2.8 rat osteosarcoma cells. The basis for this technique is to symmetrically spot in quadruplicate, on a single plate, a large number of potentially positive plaques obtained from a primary, conventional screen. We then do only one transfer from this plate in order that there will be minimal variability in DNA transfer. This filter is cut into symmetrical strips so that all clones are multiply represented on each strip. These strips are then hybridized with different probes. Since each strip contains an approximately identical amount of DNA per plaque, it is possible to accurately detect mRNAs that are induced only slightly above background. Additionally, the large sizes of the DNA plaques, as well as spotting each clone serially, contribute to the sensitivity of the technique.

Role of exposure databases in risk management

Despite the development of numerous national exposure-related databases, exposure assessment remains a weak link in the chain of risk assessment and risk-management activities. Most databases include measures of environmental releases or concentrations of pollutants in specific media, but do not include actual measures of exposure. If accurate estimates of exposure experienced by populations or individuals are absent, it is impossible to judge the effectiveness of risk-management strategies. The Risk Management Work Group evaluation identified the following needs: refinement of measurements of total exposure experienced by individuals, improved characterization of the distribution of exposures in the population, longitudinal monitoring of exposure trends, and improved information about the public health implications of exposure. Recommendations are presented with the hope that the utility of existing databases will be improved and that future initiatives will be developed that meet the needs of risk management.

Sex typing of Aratinga parrots using the human minisatellite probe 33.15

Images

Temporal neocorticectomy in management of intractable epilepsy: long-term outcome and predictive factors

We report the results of a long-term follow-up study of 50 patients who underwent removal of temporal neocortex with preservation of deeper limbic structures as surgical therapy for intractable temporal lobe epilepsy. The follow-up period ranged from 3 to 15 years. Preoperative EEG investigations were based on interictal discharges alone. Three factors were predictive of a good outcome: (a) A clear unilateral anterior-midtemporal focus (p less than 0.01), (b) stereotypical onset of temporal lobe seizure (p less than 0.005), and (c) greater volume of tissue removed at operation (p less than 0.05). Overall results showed that 62% of patients experienced an outcome of "cure" or "almost cure," as classified according to a modified version of Crandall's criteria (Crandall's I and II). Those who experienced a significant reduction in seizures but who continued to have intractable epilepsy (Crandall's III) were not considered to have had a good result. Overall outcome compares favorably with other that of centers using different surgical approaches and indicates that neocorticectomy is a suitable procedure in a highly selected population even when limited resources are available.

Multilocus DNA fingerprints in gallinaceous birds: general approach and problems

Multilocus profiles were investigated in five different species of Galliformes (ring-necked pheasant Phasianus colchicus, Indian peafowl Pavo cristatus, Japanese quail Coturnix coturnix japonica, domestic chicken Gallus gallus, and red grouse Lagopus lagopus scoticus) using two human multilocus probes (33.6 and 33.15) in combination with each of four restriction enzymes (AluI, DdeI, HaeIII or HinfI). All the species show a DNA fingerprint-like pattern using at least one restriction enzyme in combination with each multilocus probe. The number of bands detected and the value of the index of similarity for each species differ significantly between the profiles obtained with each multilocus probe. Some enzyme/probe combinations reveal strong cross-hybridization of the multilocus probes with satellite or satellite-like DNA sequences in pheasant, peacock, quail and chicken, which partially or completely prevented scoring of the profile. The choice of restriction enzyme was found to influence the number of bands, the value of the index of similarity and the probability of obtaining an identical fingerprint between unrelated individuals. The Mendelian inheritance and independent segregation of the fragments detected using AluI was investigated in three species (ring-necked pheasant, Indian peafowl and red grouse). Some bands were shown to be tightly linked. An extreme case was encountered in the red grouse, where 12 of the 15 bands scored in one parent represented only two, apparently allelic, haplotypes and so derived from a single locus. However, fingerprint patterns will often be adequate for use in paternity analyses, such as in behavioural studies, despite the occurrence of haplotypic sets of bands. Identical DNA multilocus profiles were sometimes observed between captive-bred siblings in one species. These results emphasize the desirability of determining, in each new species, the optimal experimental conditions as a preliminary to any behavioural or population genetic studies that use the multilocus DNA fingerprinting methodology.

Human autoantibodies against desmoplakins in paraneoplastic pemphigus

Recently, a previously unrecognized autoantibody mediated blistering disease, paraneoplastic pemphigus has been described. Paraneoplastic pemphigus is associated with lymphoid malignancies, thymomas, and poorly differentiated sarcomas. Serum of affected patients contain pathogenic autoantibodies that immunoprecipitate from normal keratinocytes a characteristic complex of four polypeptides with M(r) of 250, 230, 210, and 190 kD. As our preliminary studies indicated that the 250-kD and the 210-kD antigens comigrated with desmoplakins I and II, we investigated the possibility that autoantibodies against the desmoplakins were a component of this autoimmune syndrome. 11 sera from affected patients were tested by indirect immunofluorescence against desmosome containing tissues, immunoprecipitation of metabolically labeled keratinocytes, and Western immunoblotting of desmoplakins I and II that had been purified to homogeneity from pig tongue epithelium. By indirect immunofluorescence, 9 of 11 sera showed strong binding to epithelial and nonepithelial desmosomes, and 2 were weakly reactive. All 11 immunoprecipitated 250- and 210-kD bands of variable intensity that comigrated with bands identified by a murine monoclonal antidesmoplakin antibody, and immunoblotting confirmed binding of the serum autoantibodies to purified desmoplakins. This demonstrates that paraneoplastic pemphigus is the first human autoimmune syndrome in which autoantibodies against the desmoplakins are a prominent component of the humoral autoimmune response.

Dentists' attitudes to cross-infection control

The wearing of gloves by dentists undertaking clinical procedures has been recommended by many authorities as an essential element of dental surgery cross-infection control. This paper reports an investigation into patterns of glove-wearing by practising dentists, and considers the effect of practice location and practising arrangements on this issue and other aspects of cross-infection control. The results show that these factors, including the type of patient treated, may influence the pattern of glove-wearing by dentists in England and Wales. These findings suggest that groups least likely to follow the recommended infection control procedures should be targeted when assessing dental education requirements.

Chromite ore processing residue in Hudson County, New Jersey

Chromite ore processing residue occurs at over 130 sites in Hudson County, New Jersey. Many of these sites are in urban residential areas. This waste is a result of 70 years of chromate and bichromate chemical manufacturing. At least 15% of the sites contain total chromium concentrations greater than 10,000 mg/kg, with hexavalent content ranging from about 1 to 50%. Continuing leaching of this waste results in yellow-colored surface water runoff and yellow deposits on the soil surface and inside basement walls. The chemistry, environmental fate, health effects, and human exposure potentials for this waste are described.

Hypervariable minisatellite DNA sequences in the Indian peafowl Pavo cristatus

We report here for the first time the large-scale isolation of hypervariable minisatellite DNA sequences from a non-human species, the Indian peafowl (Pavo cristatus). A size-selected genomic DNA fraction, rich in hypervariable minisatellites, was cloned into Charomid 9-36. This library was screened using two multilocus hypervariable probes, 33.6 and 33.15 and also, in a "probe-walking" approach, with five of the peafowl minisatellites initially isolated. Forty-eight positively hybridizing clones were characterized and found to originate from 30 different loci, 18 of which were polymorphic. Five of these variable minisatellite loci were studied further. They all showed Mendelian inheritance. The heterozygosities of these loci were relatively low (range 22-78%) in comparison with those of previously cloned human loci, as expected in view of inbreeding in our semicaptive study population. No new length allele mutations were observed in families and the mean mutation rate per locus is low (less than 0.004, 95% confidence maximum). These loci were also investigated by cross-species hybridization in related taxa. The ability of the probes to detect hypervariable sequences in other species within the same avian family was found to vary, from those probes that are species-specific to those that are apparently general to the family. We also illustrate the potential usefulness of these probes for paternity analysis in a study of sexual selection, and discuss the general application of specific hypervariable probes in behavioral and evolutionary studies.

Multilocus and single locus minisatellite analysis in population biological studies

In this review we describe the situations in which minisatellite analysis is of value to studies of population and evolutionary biology. Evolutionary and population biologists need to be able to quantify genetic relationships among individual organisms at many different levels, from close familial relationships to evolutionarily distant phylogenetic ones. The use of minisatellite markers is put into this context and compared with the other molecular biological techniques. Examples of the use of multilocus minisatellite analysis in population biology are described. The limitations of multilocus fingerprinting are presented, together with the potential advantages of locus-specific probes. The use of locus-specific probes in population biology is now often feasible due to the recent development of a cloning system which allows their efficient isolation. The availability of locus-specific probes should significantly expand the role of minisatellite markers in population biology.

Doxorubicin resistance conferred by selective enhancement of intracellular glutathione peroxidase or superoxide dismutase content in human MCF-7 breast cancer cells

To examine the role of doxorubicin-stimulated oxyradical formation in tumor cell killing, we introduced glutathione peroxidase (GSH Px) or superoxide dismutase (SOD) into MCF-7 cells by "scrape loading." Control cytoplasmic GSH Px and SOD levels increased from (mean +/- S.E.) 0.37 nmol/min/mg and 0.58 microgram SOD/mg, respectively, to 3.99 or 7.63 nmol/min/mg and 1.40 or 1.83 micrograms SOD/mg after treatment with either 150 or 300 units/ml of GSH Px or 20 or 40 mg/ml SOD. Resistance to doxorubicin was correlated with the level of GSH Px introduced into the MCF-7 cells; a one-hour exposure to 1.75 microM doxorubicin decreased the cloning efficiency of control cells loaded with medium alone to 34%, whereas doxorubicin-treated cells augmented with 150 or 300 units/ml of GSH Px had plating efficiencies of 56 or 86%, P less than 0.05. Introduction of SOD increased MCF-7 resistance to doxorubicin similarly. The heat-inactivated enzymes were not protective. Cells loaded with GSH Px were also resistant to the redox cycling anticancer quinone mitomycin C but not to the redox inactive analogs 5-iminodaunorubicin and mitoxantrone, suggesting that amplification of GSH Px or SOD levels can produce doxorubicin resistance in MCF-7 cells.

Drinking water contamination and the incidence of leukemia: an ecologic study

An ecologic study was performed to examine the relation between the incidence of leukemias and the occurrence of volatile organic chemical (VOC) contamination of drinking water supplies within a study area comprised of subpopulations differentially exposed to drinking water VOCs (trichloroethylene and related solvents). Populations served by community water supplies were classified into exposure categories according to VOC contamination status based on 1984-85 sampling data. Leukemia incidence data (1979-84) were collected from a population-based cancer registry. For females, the standardized incidence ratio was elevated only in towns in the highest of three exposure categories. No association was observed in males in any of the exposure categories. A Poisson regression analysis of the data, using finer exposure strata, indicated an increase in risk among females with increasing level of contamination which appeared to be distributed evenly across all age strata. The rate ratio for females at the highest exposure stratum for total non-THM VOCs compared to the least exposed stratum was 1.68. The observed association appears to suggest that drinking water contaminated with VOCs may increase the incidence of leukemia among exposed females, but caution is advised in the interpretation of these results because of the uncertainties inherent in ecologic studies.

Proximal femoral replacement for pathological fracture

Nine patients presented to our unit with extensive metastatic destruction of the proximal femur. The extent of bone loss precluded the use of standard methods of fixation. We undertook proximal femoral replacement as a palliative treatment to restore mobility and relieve pain. Six patients mobilized satisfactorily postoperatively. Three patients did not regain independent mobility and died within 4 weeks of surgery. The major complication was dislocation, which occurred in two patients. The mean postoperative survival was 8 months. We believe proximal femoral replacement is a useful palliative procedure in selected cases of metastatic disease of the femur.

Sustained-release dosage forms

Transdermal drug delivery provides an effective and advantageous alternative to the oral delivery of therapeutic agents. Currently, many other drugs are being evaluated for transdermal delivery including testosterone, fentanyl, nicotine and timolol. They offer the promise of simplified dosage regimens, enhanced compliance, reduced side effects and improved therapy of disease.

Phosphorylation of class I but not class II MHC molecules by membrane-localized protein kinase C

Membranes were isolated from B cells stimulated with phorbol 12-myristate 13-acetate (PMA) for a time sufficient to allow maximal redistribution and activation of protein kinase C (PKC). Exposure of such membranes to a short incubation with [gamma-32P]ATP resulted in the detection of at least nine unique or hyperphosphorylated membrane proteins by SDS-PAGE and autoradiography. The appearance of these phosphoproteins was blocked by pretreatment of the membranes with H-7 or sangivamycin, two selective inhibitors of PKC. In addition, membranes purified from B cells treated with an inactive phorbol ester or stimulated with dibutyryl cAMP failed to exhibit a pattern of new phosphoproteins. These results are consistent with the involvement of PKC in the phosphorylation of the proteins. These phosphoproteins are also candidates for proteins whose functions are modified as a consequence of early signal delivery to resting B cells following membrane immunoglobulin occupancy. This system was utilized to identify the heavy chain of MHC class I molecules as one of the membrane proteins phosphorylated by PKC. The MHC class II molecules were not phosphorylated in membranes isolated from PMA-treated normal B cells or from PMA-treated B cells which had previously been exposed to IL-4. These results indicate that class I, but not class II, MHC molecules are phosphorylated by PKC. It is possible that such a modification of cell surface class I molecules may be involved during the process of signal transduction leading to B cell activation.

Determinants of diagnostic accuracy in pulmonary scintigraphy for pulmonary capillary protein leak associated with adult respiratory distress syndrome (ARDS): a technical note

Radionuclide assessment of pulmonary capillary protein leak using [99mTc] human serum albumin (99mTc-HSA) was first reported from our laboratory. In this study we investigated the impact of 1) sampling time post tracer injection, and 2) lung region assignment, on diagnostic accuracy between 2 groups (control n = 20 and ARDS n = 20). Each patient received 370 MBq 99mTc-HSA i.v. and was imaged for 45 min. The slope index (SI) [change in lung: heart activity ratio/min] was calculated from 11 computer assigned lung regions for intervals of 5-15 (early [E]) and 15-45 (late [L]) min. The diagnostic accuracy of E vs L SI calculations for the 11 regions was evaluated by stepwise logistic regression. E SI data and L SI data from the lower 1/3 of the lung did not achieve significance for inclusion in the discriminant model (P less than 0.05). In the nine remaining regions L SI was significant. Optimal discrimination was achieved from L SI data obtained from a region confined to the lateral half of the mid 3rd of the lung field (sensitivity 81%, specificity 85%, accuracy 83%). The results confirm that: 1) a late (15-45 min) sampling period and 2) proper region assignment are necessary to maximize accuracy of this technique.

Bilateral simultaneous rupture of the quadriceps tendons. A report of four cases and review of the literature

Four patients with bilateral simultaneous rupture of the quadriceps tendons were each older than 70 years of age. In the first patient the diagnosis was missed and one side was managed conservatively, while the other side was surgically treated. A combination of inadequate postoperative immobilization and the use of chromic catgut sutures probably caused failure of the repair, requiring revision surgery. The other three patients were treated by bilateral operative repair and had satisfactory results. Nonabsorbable suture material use and a minimum period of six weeks of postoperative immobilization are recommended.

Microdysgenesis in resected temporal neocortex: incidence and clinical significance in focal epilepsy

Fifty patients underwent superficial temporal lobectomy for intractable temporal lobe epilepsy. Total cure rate was 52%, and significant improvement was achieved in 88%. Cytoarchitectural changes in gray and white tissue were analyzed under light microscopy. Neuronal dysgenesis was correlated with the duration of seizure disorder, age of onset, and other etiologic factors, and with clinical outcome. Temporal lobes from 33 neurologically normal autopsy brains which were age- and sex-matched with patients were examined as controls. Severe neuronal ectopia (greater than 8 neurons/2 mm2 white matter) was present in 42% of patients with epilepsy and in none of controls. There was neuronal clustering in 28% of those with epilepsy, and Chaslin's (subpial) gliosis in 38%. Controls did not have these changes. The presence of severe neuronal ectopia and clustering was predictive of a favorable clinical outcome following surgery (p less than 0.05). No correlation was found between microdysgenesis and other factors. These findings suggest that the presence of neuronal dysgenesis may be of significance in the clinical outcome following surgery, and that the abnormal tissue may be important as a morphologic substrate for seizures in some patients.

Synthesis and intracellular processing of aminooligopeptidase by human intestine

Aminooligopeptidase is an intrinsic glycoprotein of the brush border membrane important for hydrolysis of the oligopeptide products of intraluminal protein digestion. To study its synthesis and intracellular processing, we performed pulse-chase experiments using [35S]methionine to label proteins of cultured human intestinal explants obtained by endoscopic biopsy. Aminooligopeptidase was isolated by immune precipitation with a monoclonal antibody and its molecular size was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. A precursor of relative molecular weight (Mr) 127,000 appeared within 10 min of chase and appeared to begin conversion to an Mr 150,000 form (the size of brush border membrane aminooligopeptidase) within 60 min. To determine if the change in molecular size was the consequence of alterations in glycosylation, we studied the susceptibility of the two forms to endo-beta-N-acetylglucosaminidase H, which cleaves immature high-mannose N-linked carbohydrate chains, and to peptide: N4-(N-acetyl-beta-glucosaminyl)asparagine amidase, which cleaves both the high-mannose and complex N-linked carbohydrate chains. Only the early Mr 127,000 aminooligopeptidase was sensitive to endo-beta-N-acetylglucosaminidase H, suggesting that the larger form results from trimming of high-mannose cores and adding terminal sugars in the Golgi complex. Both forms were sensitive to peptide: N4-(N-acetyl-beta-glucosaminyl)asparagine amidase, generating an Mr 114,000 species. The kinetics of the synthesis and processing of aminooligopeptidase and sucrase-isomaltase were compared by immunoprecipitation of both proteins from the same tissue after separating the microvillous membrane from the remainder of the cellular membranes. Labeled aminooligopeptidase was present intracellularly in its mature form within 60 min and was detected exclusively in the brush border membrane by 90 min. Most of the labeled sucrase-isomaltase pool had not yet undergone complex glycosylation during the same period. These data demonstrate that although human intestinal aminooligopeptidase undergoes N-linked glycosylation like sucrase-isomaltase, the synthesis of aminooligopeptidase differs from that of sucrase-isomaltase in respect to the absence of a high-molecular-weight precursor and more rapid pre-Golgi processing.

Organization and expression of a second chromosome follicle cell gene cluster in Drosophila

Four genes expressed during the period of vitelline membrane formation are clustered within 8 kb of DNA in region 26A of the second chromosome. Temporal and quantitative difference in the profiles of accumulated RNA suggest that the genes are independently regulated although they are selectively expressed during the stages of vitelline membrane biosynthesis. In situ hybridization and S1 analyses of RNAs from fractionated eggchambers established that these genes are active only in the follicle cells. S1 mapping with in vitro synthesized RNA probes shows that three of the genes are tandemly oriented. All four appear to be intronless. In vitro translation products from hybrid-selected RNAs indicate that two of these genes code for major vitelline membrane proteins. Sequence analysis of these two genes support this conclusion. The cell- and stage-specific expression of the other two genes, encoding less abundant RNAs, suggests that they also play a role in early eggshell production.

Vulvar dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans of the vulva is an extremely rare neoplasm. This low-grade sarcoma of the dermis clinically appears to be encapsulated but microscopically has tumor projections well away from the central nodules. Wide local excision is the recommended treatment for dermatofibrosarcoma protuberans; however, a more radical surgical approach may be needed to obtain clear surgical margins. The following case study present the fifth reported patient with this unusual neoplasm on the vulva.

Characterization and sequence of follicle cell genes selectively expressed during vitelline membrane formation in Drosophila

To isolate genes involved in vitelline membrane production, an ovarian cDNA library was screened with eggchamber RNAs labeled in vivo. Two cDNA clones encoding RNAs that are selectively expressed in follicle cells during the period of vitelline membrane formation were isolated. Following isolation of homologous genomic clones from a Drosophila library, one gene was localized by in situ hybridization to chromosomal region 26A, and the other to 3C. Developmental Northern blots demonstrated that both genes produce 700-800 nucleotide transcripts that accumulate during the stages of vitelline membrane synthesis. In vitro translation products from hybrid selected RNAs and DNA sequence analysis both indicate that the 26A region gene encodes a major protein component of the vitelline membrane. The structural properties of the 3C region follicle cell gene seem more compatible with an intracellular function.