Relative mitogenic activities of wild-type and retinoblastoma binding-defective SV40 T antigens in serum-deprived and senescent human diploid fibroblasts

A novel gene transfer approach was used to investigate whether the retinoblastoma (Rb)-binding domain of simian virus 40 (SV40) T antigen is required for efficient T antigen-mediated stimulation of DNA synthesis is quiescent or senescent human embryo fibroblasts. In senescent cells, comparison between wild-type T antigen and a mutant defective in Rb binding (Glu-107-->Lys) revealed the latter to have approximately 15-fold lower activity. In contrast, comparison of wild-type and Rb- T antigens in serum-deprived quiescent cells revealed a much smaller (1.8-fold) difference. Surprisingly, an 18-fold differential could be induced by treating quiescent cells with the differentiating agent sodium butyrate. These results suggest that the role of Rb in control of the cell cycle is strongly dependent on the physiological state of the cell and the mechanism of growth arrest.

Peptide YY ameliorates cerulein-induced pancreatic injury in the rat

Peptide YY (PYY), a known inhibitor of both pancreatic secretion and the release of cholecystokinin (CCK), may play a role in the pathophysiology of acute pancreatitis (AP). Supramaximal stimulation of the pancreas with CCK, or its analogue cerulein, induces edematous AP. We previously documented significant decreases in plasma PYY in sodium taurocholate-induced AP in the anesthetized pig, with exogenous PYY suppressing plasma amylase activity. We hypothesized that PYY may ameliorate cerulein-induced pancreatic injury in a conscious animal model. Thirty-two male Sprague-Dawley rats underwent chronic cannulation of the jugular vein and carotid artery for drug infusion and blood sampling. The animals were allowed to recover from anesthesia for a minimum of 16 hours, after which they were randomized to one of four (n = 8) treatment groups (cerulein 10 micrograms/kg/h, PYY 400 pmol/kg/h, cerulein+PYY, and control-saline 2 mL/kg/h). All treatments were administered by intravenous infusion over the first 6 hours of the experiment. Blood samples were taken prior to infusion and at 1, 3, 6, 9, and 24 hours into the study; the rats were then killed and the pancreata removed for weighing and histologic examination. All pancreatic specimens were graded in a blinded fashion for vacuolization, edema, inflammation, and necrosis. The mean basal plasma amylase level for all animals was 1,171 +/- 100 U/L and was not significantly different between groups. Infusion of cerulein resulted in significant increases in plasma amylase levels at 3, 6, 9, and 24 hours (4,827 +/- 1,022 U/L at 24 hours). In the group receiving both cerulein and PYY, the hyperamylasemia was attenuated with a return to basal values at 24 hours (1,206 +/- 103 U/L). There was significant pancreatic weight gain (1.99 +/- 0.07 g versus 1.03 +/- 0.07 g) and a worsened histologic picture in cerulein-treated animals compared with control animals (worsened edema, necrosis, and vacuolization). The addition of PYY to cerulein resulted in significantly lower pancreatic weight (1.27 +/- 0.11 g) than in the non-PYY-treated rats receiving cerulein. Pancreatic weight was not significantly different in this group compared with the control group. In addition, pancreatic histologic findings were significantly improved in those rats receiving PYY (decreased vacuolization and necrosis). Amylase levels, pancreatic weight, and morphologic findings were not significantly changed compared with basal values in the control or PYY alone treated groups. e conclude that as an inhibitor of pancreatic exocrine secretion, PYY ameliorates cerulein-induced pancreatic injury in the conscious rat.

Lingual tonsillar hypertrophy causing failed intubation and cerebral anoxia

Hypertrophy of the lingual tonsils is an unusual condition that may cause complications such as airway obstruction, abscess, sleep apnea, and recurrent epiglottitis. There have been reports of difficult anesthesic intubation in children with enlarged lingual tonsils. We describe a 24-year-old woman whose markedly hypertrophied lingual tonsils prevented intubation after anesthesic relaxation during preparation for appendectomy.

Recent trends in the identification and treatment of high blood cholesterol by physicians. Progress and missed opportunities

OBJECTIVE

To investigate recent trends in the percentage and characteristics of patients being treated by a physician for high blood cholesterol (HBC) and to assess missed clinical opportunities to screen for HBC.

DESIGN, SETTING, PARTICIPANTS

Telephone interviews of 154,735 adults in 37 states that participated in the Behavioral Risk Factor Surveillance System during 1988-1990 to assess trends in the percentage of patients treated for HBC by a physician. An opportunity was considered missed if a person did not report being screened for HBC despite seeing a physician for preventive care in the last 2 years.

RESULTS

Between the first quarter of 1988 and the last quarter of 1990, the percentage of persons treated by a physician for HBC increased from 7.6% to 11.7% (P < .001). However, since an estimated 36% of US adults need treatment for HBC, fewer than one third of persons who need treatment are receiving it. Persons with two or more cardiac risk factors were more likely to be treated, while men, blacks, persons in lower socioeconomic groups, and persons between 20 and 34 years of age were less likely to be treated. Among the 126,571 persons who had seen a physician for preventive care within the last 2 years, missed opportunities to screen for HBC were most common among persons aged 20 through 34 years (59%) and among women who had seen obstetricians/gynecologists for preventive care (43%).

CONCLUSIONS

Fewer than one third of persons who need treatment for HBC as estimated by data from the second National Health and Nutrition and Nutrition Examination Survey are receiving treatment. Better use of clinical opportunities to screen for HBC could substantially accelerate the progress in identifying persons, young adults in particular, who are likely to benefit from cholesterol reduction.

Genome walking with 2- to 4-kb steps using panhandle PCR

Panhandle PCR is a method that permits the rapid retrieval of DNA segments flanking a known DNA sequence. This method extends the application of PCR to the retrieval of DNA where only one end of the DNA sequence is known, so that one can use PCR to walk along an uncharacterized stretch of DNA. In this report, we demonstrate that this method can be applied to the highly specific retrieval of large pieces (2.2-4.4 kb) of human genomic DNA that flank the primer annealing sites.

Spontaneous compartment syndrome in a patient on long-term anticoagulation

The case is reported of a 35-year-old lady on long-term anticoagulation with warfarin who developed a spontaneous acute compartment syndrome in the forearm. Despite a delay in diagnosis, an extensive decompression resulted in complete recovery.

Stability and detection of recombinant pre-pro-concanavalin A after cytoplasmic expression in Escherichia coli

The cDNA for pre-pro-concanavalin A (pre-pro-Con A) from Canavalia ensiformis was used to construct two cytoplasmic expression vectors: pKconA (no transcription terminator) and pTKconA (containing the cry transcription terminator). The latter produced 2- to 3-fold greater amounts of pre-pro-Con A. This product containing the plant signal can be detected by Western blotting only after electrophoretic transfer in the presence of SDS, indicating reduced solubility. The signal is not removed and pre-pro-Con A is clearly stable after expression in E. coli JM109. The protein is not cleaved and ligated as in the plant, in contrast to a recent report.

Cutaneous malignant melanoma, Scotland, 1979-89. The Scottish Melanoma Group

The Scottish Melanoma Group (SMG) was established in 1979 to assess mortality from and incidence, features, pathological data, and management of cutaneous malignant melanoma in Scotland. Incidence during the first five years and five-year survival have already been reported. We now have data about incidence and mortality over eleven years in relation to anatomical site and pathological types. From 1979 to 1989, 1354 male and 2459 female patients with primary cutaneous malignant melanomas were first diagnosed in Scottish residents. The incidence rate per 100,000 population per year has increased from 3.4 in 1979 to 7.1 in 1989 for men, and from 6.6 to 10.4 for women. The overall increase over eleven years is 82% (7.4% per year). The greatest rates of increase are seen in lesions of the superficial spreading histogenetic type, arising on the female leg and the male trunk. Following public education programmes started in 1985, the proportion of all melanomas less than 1.5 mm thick has shown a sustained and significant increase. Mortality data for 1661 patients for whom a minimum of five-year follow-up is available shows five-year survival of 71.6% overall (77.6% for women, 58.7% for men). The survival advantage for women persists when appropriate statistical adjustment is made for thickness, ulceration, and histogenetic type. These data are useful in designing public education programmes aimed at both primary and secondary prevention of melanoma and in auditing changes in trends that might result from such education.

Nucleotide sequence of the structural gene encoding a 2-haloalkanoic acid dehalogenase of Pseudomonas putida strain AJ1 and purification of the encoded protein

The nucleotide sequence of a gene encoding an L-2-haloalkanoic acid halidohydrolase from Pseudomonas putida strain AJ1 was determined. The ORF (hadL) codes for a polypeptide of 227 amino acids (Mr 25,687) which has significant homology to two other L-2-haloalkanoic acid halidohydrolases of Pseudomonas sp., DehcI and DehcII; these show 38% and 51% amino acid identity respectively to HadL. All three enzymes produce products of an opposite optical configuration to that of the substrates. Comparison of the three sequences shows several highly conserved motifs which indicate the possible position of the enzyme active site. The enzyme was purified to homogeneity and appears to exist as a tetramer.

Recombinant circle PCR and recombination PCR for site-specific mutagenesis without PCR product purification

Two simple methods for site-specific mutagenesis are described and compared. In each method, the PCR is used in two separate amplifications to mutate the site of interest and to add ends to one PCR product that are homologous to the ends of the other PCR product. In the first method, the two products are combined, denatured and reannealed prior to transformation of E. coli in order to form recombinant circles in vitro, while in the second method, the two linear products are co-transfected directly into E. coli without prior manipulation, resulting in transformation of E. coli with the recombinant of interest by recombination in vivo. Each PCR amplification uses a plasmid template that has been linearized by restriction enzyme digestion outside the region to be amplified. This permits use of unpurified PCR products in these two protocols and generation of the mutant of interest with no other enzymatic manipulation in vitro apart from PCR amplification. In each protocol greater than or equal to 50% of the resulting clones contained the mutation of interest without detected errors.

Non-glycosylated recombinant pro-concanavalin A is active without polypeptide cleavage

The complex post-translational processing of concanavalin A (Con A) in maturing jackbeans is unique because the non-glycosylated mature active protein is circularly permuted in primary sequence relative to its own inactive precursor (glycosylated pro-Con A) and to other legume lectins. We show here that non-glycosylated pro-Con A expressed in bacteria from recombinant cDNA (rec-pro-Con A) folds in vivo and in vitro to a stable form which is active without further processing. N-glycosylation alone must therefore be sufficient to inactivate pro-Con A--a novel role for glycosylation in regulating activity during protein maturation.

Sequence specific generation of a DNA panhandle permits PCR amplification of unknown flanking DNA

We present a novel method for the PCR amplification of unknown DNA that flanks a known segment directly from human genomic DNA. PCR requires that primer annealing sites be present on each end of the DNA segment that is to be amplified. In this method, known DNA is placed on the uncharacterized side of the sequence of interest via DNA polymerase mediated generation of a PCR template that is shaped like a pan with a handle. Generation of this template permits specific amplification of the unknown sequence. Taq (DNA) polymerase was used to form the original template and to generate the PCR product. 2.2 kb of the beta-globin gene, and 657 bp of the 5' flanking region of the cystic fibrosis transmembrane conductance regulator gene, were amplified directly from human genomic DNA using primers that initially flank only one side of the region amplified. This method will provide a powerful tool for acquiring DNA sequence information.

Successful use of subcutaneous recombinant human erythropoietin before cholecystectomy in an anemic patient with religious objections to transfusion therapy

Use of recombinant human erythropoietin has been advocated for therapy in anemic patients with end-stage renal disease and to enhance the harvesting of autologous red blood cells from healthy patients scheduled for elective orthopedic surgery. The authors report the case of a diabetic patient with moderate chronic renal failure and cholelithiasis but whose religious beliefs forbade the use of transfusion therapy. She underwent successful cholecystectomy only after treatment with recombinant human erythropoietin.

Cardiovascular health knowledge in the United States: findings from the National Health Interview Survey, 1985

Knowledge of the risk precursors to cardiovascular disease is thought to be a key component of health decision making. Many intervention programs have been aimed at increasing the nation's general knowledge of risk factors for cardiovascular disease, although the determinants of the level of cardiovascular disease knowledge are not thoroughly understood. We examined cardiovascular knowledge in a nationally representative sample of the United States population with data from the 1985 Health Promotion and Disease Prevention supplement of the National Health Interview Survey. Interviews with 12,551 white women, 770 Hispanic women, 2,547 black women, 9,832 white men, 576 Hispanic men, and 1,440 black men were used in this analysis. We constructed a seven-item index for cardiovascular disease knowledge. After adjustment for age and education, white men and women scored higher on the cardiovascular disease knowledge index than either their Hispanic or black counterparts. We also examined the relationships of age, education, income, marital status, access to medical care, geographic region, and seven self-reported cardiovascular disease risk factors to the levels of cardiovascular disease knowledge. Education was the strongest predictor of cardiovascular disease knowledge. The variables examined accounted for a small portion of the variance in knowledge. Levels of cardiovascular disease knowledge were lower among respondents with less education and income, those who were not married, those with less access to medical care, and those who were smokers or physically inactive. Therefore, efforts to improve levels of cardiovascular disease knowledge should be directed toward subgroups.

Fluid therapy in the PACU

The goal of fluid therapy in the PACU setting is the restoration of blood volume and tissue perfusion. Choosing the type of fluid infusion depends on the preoperative, intraoperative, and postoperative condition of the patient. An understanding of the functional fluid compartments, the composition of body fluids and commercially available fluids, and the steps to evaluate fluid depletion allow one to determine the fluid needs of the patient. The orderly and expedient evaluation of fluid status of the postoperative patient involves the assessment of volume status, concentration status, composition status, and signs and symptoms of inadequate tissue perfusion. Recovery after surgery is a dynamic process, and fluid reassessment should be conducted periodically. Fluid challenges may be necessary in the hypovolemic patient or in patients with clear signs and symptoms of end-organ hypoperfusion. Weil and Rackow and Shoemaker provide useful approaches to fluid challenge guided by CVP and PAP monitoring. The decision of whether to use crystalloids or colloids for fluid resuscitation is complex, controversial, often determined by personal preference and concern over expense, and may be inconsequential as long as fluids are infused appropriate to the needs of the patient. There are disadvantages and advantages to both crystalloid and colloid fluid administration. As with any therapeutic intervention, there are complications with fluid administration, congestive heart failure and pulmonary edema being of more immediate concern. Finally, blood components are colloid-type solutions that should be reserved for specific patient problems. Red blood cells are indicated to increase oxygen-carrying capacity in patients with anemia. Platelets are used to treat bleeding associated with deficiencies in platelet number or function. Fresh frozen plasma is transfused to increase clotting factor levels in patients with demonstrated deficiency. A good understanding of fluid types available, of a systematic approach to evaluating fluid depletion, and of the indications for blood component therapy will allow one to make appropriate decisions when implementing fluid therapy in the PACU.

A rapid method for recombination and site-specific mutagenesis by placing homologous ends on DNA using polymerase chain reaction

We have developed a novel polymerase chain reaction (PCR) method that permits the rapid generation of site-specific mutants and recombinant DNA constructs with a minimum number of steps and primers. DNA segments are modified by using amplifying primers that add homologous ends to the polymerase chain reaction product(s). These homologous ends undergo recombination in vivo following transformation of recA-E. coli strains used routinely in cloning. In vivo circularization of PCR products containing plasmid sequences with a selective marker permits the rapid cloning of the desired mutant or recombinant. In the mutagenesis protocol, 7 of the 12 clones contained the product of interest, and 6 of these clones had no detected error (50% of the clones without detected errors). In each of several recombination protocols, at least 50% of the clones tested contained the insert of interest without detected errors.

Health risk factors among the Amish: results of a survey

The Amish are a unique societal subgroup deliberately setting themselves apart from the modern world through religious beliefs and practices. Few reports and no systematic studies have been conducted on Amish health behaviors. A representative sample of 400 Amish adults residing in Holmes County, Ohio, were interviewed using the Behavioral Risk Factor Survey (BRFS). For comparison, a representative sample of 773 non-Amish adults responded to the same survey through telephone interviews. Prevalence of self-reported hypertension was lower among Amish than non-Amish, obesity was greater among Amish than non-Amish women but similar among men, and stress responses were more prevalent among Amish than non-Amish. While some differences between groups could be influenced by response biases, many are supported by less systematic observations of Old Order Amish societies. Patterns of health behavior reflect characteristics of Amish culture and may be responsible for certain favorable mortality rates among the Amish population. Need for cultural sensitivity is evident in health promotion program design and implementation.

DNA mutagenesis and recombination

The polymerase chain reaction is used for site-specific mutagenesis and for DNA recombination without any enzymatic reaction in vitro, apart from DNA amplification.

Trauma services requirements in a district general hospital serving a rural area

OBJECTIVE

To assess the demands made on a regional trauma centre by a district trauma unit.

DESIGN

Two part study. (1) Prospective analysis of one month's workload. (2) Retrospective analysis of one year's workload by using a computer based records system. Comparison of two sets of results.

SETTING

Accident unit in Gwynedd Hospital, Bangor.

PATIENTS

(1) All patients who attended the accident unit in August 1988. (2) All patients who attended the accident unit in the calendar year April 1988-April 1989.

MAIN OUTCOME MEASURE

Workload of a district trauma unit.

RESULTS

In August 1988 there were 2325 attendances; 2302 of these were analysed. In all, 1904 attendances were for trauma; 213 patients were admitted to the trauma ward and 103 required an operation that entailed incision. Patients who attended the unit had a mean (range) injury severity score of 2-13 (0-25). Only two patients had injuries that a district general hospital would not be expected to cope with (injury severity score greater than 20). In the year April 1988-April 1989, 21,007 patients attended the unit. In all, 17,958 attendances were for orthopaedic injuries or injuries caused by an accident; 1966 patients were admitted to the unit.

CONCLUSIONS

Most trauma is musculoskeletal and relatively minor according to the injury severity score. All but a few injuries can be managed in district general hospitals. In their recent report the Royal College of Surgeons has overestimated the requirements that a British district general hospital would have of a regional trauma centre.

A rapid method for site-specific mutagenesis and directional subcloning by using the polymerase chain reaction to generate recombinant circles

Site-specific mutagenesis and directional subcloning were accomplished by using the polymerase chain reaction to generate products that can recombine to form circular DNA. This DNA was transfected into E. coli without phosphorylation of primers, restriction enzyme digestion or ligation. Specifically, the polymerase chain reaction was used to generate products that when combined, denatured and reannealed, form double-stranded DNA with discrete, cohesive single-stranded ends. The generation of these cohesive ends of DNA permits the formation of precise, directional DNA joints without dependence on enzyme restriction sites. The primers were designed such that these cohesive single-stranded ends annealed to form circular DNA. The recombinant of interest was generated following only 14 amplification cycles. These recombinant circles of DNA were directly transfected into E. coli. In the mutagenesis protocol, the desired mutant was obtained at 83%-100% efficiency. Unwanted mutations were not detected, indicating a less than 0.025% nucleotide misincorporation frequency. In the directional subcloning protocol, inserts were positioned precisely in the recipient plasmid and were in the correct orientation. One unwanted mutation was detected after sequencing 900 bases, indicating a 0.11% nucleotide misincorporation frequency. Each manipulation, from setting up for the DNA amplification to transfection into E. coli. can easily be accomplished in one day.

High dose intensity combination chemotherapy for advanced epithelial ovarian carcinoma: results of a pilot study

Retrospective studies have recently demonstrated a significant correlation between dose intensity of chemotherapy and response rates and survival in various diseases including epithelial ovarian carcinoma. As part of a proposed randomised trial to assess the effect of dose intensity on outcome in ovarian carcinoma, a pilot study has been undertaken to determine the toxicity and efficacy of the high intensity therapy. Nineteen patients with advanced ovarian carcinoma received initial treatment with cisplatin 120 mg m-2 i.v. day 1, and cyclophosphamide 1,000 mg-2 i.v. day 1, given at 21-day intervals for six cycles. The average relative dose intensity of this therapy is 1.14 when compared with the CHAP regimen. Severe toxicity was experienced by most patients. The median received average relative dose intensity was 0.90, with only one patient receiving treatment to the proposed intensity. Randomised studies of the effect of dose intensity in ovarian carcinoma are essential, but an initial step must be to assess whether the proposed high dose treatment can be delivered.

Subcellular distribution and mobilization of MAC-1 (CD11b/CD18) in neonatal neutrophils

The CD11b/CD18 (Mac-1) heterodimeric surface glycoprotein contributes to a broad range of adherence-dependent neutrophil inflammatory functions. Previous investigations have indicated that diminished expression or regulation of Mac-1 may underlie abnormalities of stimulated adhesion and chemotaxis of neonatal neutrophils in vitro and inflammatory deficits in human neonates. To define the pathogenic mechanisms contributing to these findings, we compared the distribution and translocation of Mac-1 in subcellular fractions of neonatal and adult neutrophils before and after chemotactic stimulation. The total cell content of Mac-1 and the proportions of Mac-1 in beta fractions (vitamin B12 binding protein-rich granules), pre-gamma fractions (gelatinase-rich granules), or gamma fractions (plasma membrane) of neonatal neutrophils were comparable with those of adult neutrophils. However, after stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 nmol/L, 37 degrees C, 15 minutes), neonatal neutrophils demonstrated (1) diminished translocation of Mac-1 from pre-gamma fractions (P less than .05), and (2) diminished surface expression of Mac-1 (P less than .05), as compared with healthy adult neutrophils. As shown in enzymatic and immunochemical assays, neonatal cells contained significantly (P less than .01) diminished levels of neutrophil gelatinase. In response to FMLP (0.1 to 10 nmol/L, 37 degrees C, 15 minutes), neonatal suspensions also released significantly (P less than .001) less gelatinase, as compared with adult neutrophil suspensions. These observations demonstrate that diminished mobilization of Mac-1 from gelatinase-rich granular pools in neonatal neutrophils is associated with abnormal surface expression of this glycoprotein after chemotactic stimulation. This abnormality may contribute, in part, to abnormal migratory properties of neonatal neutrophils in response to inflammatory stimuli.

Disability glare and hydrogel lens wear--revisited

Decreased tolerance to glare is a common complaint among hydrogel contact lens wearers. Recently this subjective complaint was measured and quantified in our laboratory in five subjects by determining increment thresholds as a function of background luminance and glare source location for both spectacles and hydrogel lens refractive corrections. Additional testing, using the same apparatus and similar protocols, has not entirely supported the original result. After testing a total of 15 subjects, data averaged across all subjects revealed no significant hydrogel contact lens-induced increases in disability glare; however, analysis of individual data revealed three classes of effects within the population tested. Subjects either demonstrated a significant glare effect induced by contact lens wear (6 of 15), no increase in disability glare (7 of 15), or a significant decrease in disability glare (2 of 15).

The activity of phosphoenolpyruvate carboxykinase throughout the lactation cycle of the guinea pig mammary gland

The enzyme phosphoenolpyruvate carboxykinase (PEPCK) has been measured in the guinea pig mammary gland throughout the pregnancy-lactation cycle. This is of interest since the primary importance of PEPCK is thought to be its role in gluconeogenesis and it is questionable whether or not gluconeogenesis occurs in the mammary gland. The enzyme activity, present in both the cytosol and mitochondria, was shown to follow the lactation profile. During the transition into lactation, cytosolic PEPCK activity increases 11-fold and mitochondrial PEPCK activity 43-fold while tissue weight increases 4-fold. Fructose 1,6-bisphosphatase was found to increase at a rate only slightly greater than that of the tissue weight. The increase in mitochondrial PEPCK activity is thus about 10 times greater than that of general tissue expansion, whereas the cytosolic PEPCK activity increase is only 2-fold greater. The activity of fructose 1,6-bisphosphatase appears to be merely keeping pace with general tissue expansion. The mitochondrial enzyme constitutes 59 +/- 3% of the total gland PEPCK activity in the prepartum state and 86 +/- 2% at midlactation. Therefore, mitochondrial PEPCK is the isoenzyme undergoing the greater increase during the transition into lactation in the guinea pig mammary gland and thus would appear to play the more important role in the conversion of oxalacetate to phosphoenolpyruvate in this tissue.

Involvement of the ileocaecal region by non-Hodgkin's lymphoma in adults: clinical features and results of treatment

Between January 1977 and January 1988, 19 patients with non-Hodgkin's lymphoma (NHL) involving the ileocaecal region were cared for by the CRC Wessex Medical Oncology Unit. Fifteen of these patients had primary ileocaecal NHL (stages IE or IIE) and four had secondary involvement of this region (stage IV). The commonest clinical presentation was with abdominal pain and a palpable mass in the right iliac fossa. Bulky (greater than 10 cm) disease was a particularly common feature, and complete surgical removal was possible in only seven patients. All patients had intermediate (18) or high grade (one) NHL using the Working Formulation. The commonest histological subtype was diffuse large cell. Seventeen patients received postoperative therapy, comprising local radiotherapy in one and combination chemotherapy in the remaining 16. Eleven of the 19 patients remain disease-free 6-60 months from diagnosis. Because of the high incidence of bulky disease at this site, postoperative therapy may be indicated, even for patients with apparently completely excised stage I disease.

Behavioral risk factors in an Amish community

A representative sample of 400 Amish adults residing in Holmes County, Ohio, was interviewed about certain health risk characteristics and behaviors, using the Behavioral Risk Factor Survey (BRFS). For purposes of comparison, a representative sample of 773 non-Amish adults responded to the same survey by telephone interviews. In general, the Amish report lower rates of alcohol and tobacco consumption than their non-Amish counterparts. The Amish are less likely to salt their food and are more likely to take vitamin supplements, but do not differ from non-Amish in the consumption of "health foods." Amish men and women are less likely to be trying to lose weight than their non-Amish counterparts. Further, the Amish are less likely to engage in leisure-time physical activity or in exercise associated with attempts to lose weight or deal with hypertension. Amish women are less likely to use seat belts than non-Amish women, whereas men in both groups appear rather similar. Although some differences could be influenced by response biases, many are supported by less systematic observations of Old Order Amish societies. The patterns of health behavior reflect characteristics of Amish culture and may be responsible for certain favorable mortality rates among the Amish population.

ChlVPP chemotherapy in advanced Hodgkin's disease

Between March 1978 and January 1987 54 patients with advanced Hodgkin's disease (HD) or relapse following radiotherapy (RT) for Hodgkin's disease have been treated with combination chemotherapy consisting of chlorambucil, vinblastine, procarbazine and prednisolone (ChlVPP). A subgroup of five patients with bulky mediastinal disease received mantle RT in addition to ChlVPP chemotherapy. Forty-two patients (77.8%) entered complete remission with 33 (61.0%) remaining in unmaintained remission and 44 (81.5%) alive at a median follow up of 51 months (range: 22-103). The treatment was generally well tolerated with minimal toxicity. ChlVPP is effective first-line treatment for Hodgkin's disease with results which may be comparable to those achieved for MOPP but with significantly less toxicity.

Monoclonal antibodies as targeting agents for cytotoxic compounds in vivo: a current assessment

Monoclonal antibodies have proved useful in the in vitro diagnosis of tumour type. Radiolabelled antibodies have also been investigated as targeting agents for the in vivo diagnosis of tumour metastasis. These studies have revealed the potential of using 'targeting agents' to identify tumours, but in addition have exposed some of the problems associated with the technique. This review describes our experiences using radiolabelled antibodies for the identification and treatment of tumours arising from the neuro-ectoderm. Based on a small number of 4 patients studies, we conclude that there are limitations on the use of radiolabelled antibodies for targeting isotopes to primary tumour masses. In addition, we outline a possible important role for antibodies in targeting therapeutic agents to minimal residual disease and diffuse tumours presenting as micro-metastasis.

Primary cutaneous neuroendocrine (Merkel cell or trabecular carcinoma) tumour of the skin: a radioresponsive tumour

Four patients with primary neuroendocrine carcinoma of the skin (Merkel cell or trabecular carcinoma) are reported to document their response to radiotheraphy. In three patients there was complete response following radiation treatment, with no local recurrence, whilst the other patient died later with distant metastases. In one patient, post-operative irradiation after excision of an involved local node prevented the growth of further tumour in this nodal group but the unirradiated primary site recurred after initial wide local excision only. This rare tumour appears to be radioresponsive, and although more clinical data are required, we would advocate a wider study of radiotherapy to the primary lesion after biopsy or excision biopsy, in association with prophylactic nodal irradiation. These tumours occur predominantly in elderly people in whom the avoidance of extensive surgery is particularly desirable.

Quantitation of intracellular Mac-1 (CD11b/CD18) pools in human neutrophils

The adhesive glycoprotein Mac-1 (CD11b/CD18) of the CD11/CD18 complex contributes to multiple neutrophil inflammatory functions. Activation of neutrophils by chemotactic stimuli results in a rapid, protein synthesis-independent increase in surface Mac-1 derived from incompletely defined intracellular compartments. Therefore, we developed a novel quantitative lectin immunoblot technique to define intracellular pools of Mac-1 in subcellular neutrophil fractions resolved on discontinuous Percoll gradients. In cavitates of unstimulated neutrophils, 30% and 26% of total Mac-1 was identified in beta [1.10 gm/ml; vitamin B12 binding protein (vit B12 B.P.)-rich] or pre-gamma (1.07 gm/ml; vit B12 B.P.-poor) granular fractions, respectively, whereas 24% was associated with the plasma membrane-rich gamma (1.06 gm/ml) fractions. N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation (10(-8) M, 15 min, 37 degrees C) significantly diminished Mac-1 in pre-gamma (-18% of total, P less than 0.05) but not beta fractions (+6% of total). Under these conditions, the content of Mac-1 in gamma fractions increased 13% in association with four- to eightfold increase in surface Mac-1 expression (OKM-1 binding). These findings suggest that chemotactic stimuli increase plasma membrane and/or surface Mac-1 on human neutrophils by mobilizing a novel intracellular granule pool.

Two routes for 99mTc-DMSA uptake into the renal cortical tubular cell

Critical factors determining the renal handling of 99mTc-dimercaptosuccinic acid (DMSA) are protein binding in plasma and the renal 99mTc-DMSA extraction efficiency. Comparison of the count rate over soft tissue with that over the cardiac blood pool about 1 h after injection demonstrated that 99mTc-DMSA is not exclusively an intravascular label. 99mTc-DMSA was 76% protein bound in plasma as demonstrated by HPLC and gel filtration. Assuming that the 24% that is not protein bound is filtered at the glomerulus, the renal extraction efficiency of 99mTc-DMSA by glomerular filtration is about 5%. Since the total renal extraction efficiency was also found to be about 5%, the majority of the activity that becomes fixed in the renal cortex arrives there as a result of filtration followed by tubular reabsorption rather than by direct extraction from peritubular blood. However, discordant changes in DMSA and DTPA uptake induced by captopril in renovascular hypertension (RVH) suggested that a minority of uptake was by direct peritubular extraction. This kinetic model was supported by indirect measurement of protein binding and extraction efficiency based on the kinetics of 99mTc-DMSA disappearance from plasma and kinetics of uptake in the kidneys. Furthermore, differential functional studies based on 99mTc-DMSA and 99mTc-DTPA before and after captopril in patients with RVH due to unilateral renal artery stenosis confirmed filtration followed by tubular reabsorption as the predominant route for DMSA uptake by the kidney.

Determining the feasibility of a heart transplant program

The careful information gathering by the task force provided a foundation for informed decision making. Furthermore, the participation of the affected constituencies in the planning process helped in building a consensus in support of the new program. The group felt confident that the relevant risks and potential benefits had been identified in the feasibility assessment. Finally, the financial forecasts provided quantified benchmarks to use in measuring the performance of the program on ongoing basis.

Mutagenic potential of binary mixtures of nitro-polychlorinated dibenzo-p-dioxins and related compounds

The mutagenic potential of binary mixtures of nitro-polychlorinated dibenzo-p-dioxins and other environmentally related compounds was determined using Salmonella typhimurium strain TA98 in the standard plate incorporation assay. Samples tested included binary mixtures of 4-nitro-4'-chlorobiphenyl with 6-nitro-4,2',3',4',5'-pentachlorobiphenyl, 4-nitrobenzo-p-dioxin with 4-nitro-2,3,8-trichlorodibenzo-p-dioxin, and benzo[a]pyrene with either nitropentachlorobiphenyl or nitrotrichlorodibenzo-p-dioxin. Inhibition was the primary interaction observed for the mixtures of polyhalogenated dioxins or biphenyls with the direct-acting mutagens nitrodibenzo-p-dioxin or nitrochlorobiphenyl. At the highest dose tested, nitrotrichlorodibenzo-p-dioxin inhibited the bacterial mutagenicity of nitrodibenzo-p-dioxin by almost 50%, while pentachlorobiphenyl inhibited the mutagenicity of nitrobiphenyl by 34%. Conversely, synergism was the primary interaction observed for mixtures of halogenated aromatics with the promutagen benzo[a]pyrene. The addition of nitrotrichlorodioxin to benzo[a]pyrene enhanced the mutagenicity of the latter compound by as much as 70%, while the mutagenic potential of a mixture of benzo[a]pyrene and nitropentachlorobiphenyl was approximately 50% greater than the mutagenicity of benzo[a]pyrene alone. In summary, mixtures of nonmutagenic nitropolyhalogenated biphenyls or dibenzo-p-dioxins appear to inhibit the mutagenicity of direct-acting mutagens, while these same compounds seem to enhance the mutagenic potential of the promutagen benzo[a]pyrene.

The effects of aspirin, dipyridamole and warfarin in femorodistal reconstruction: long-term results

This study was done to evaluate the effect of aspirin (ASA), dipyridamole (DIP), and warfarin on 406 patients who had femoropopliteal-tibial operations with saphenous vein (SV), umbilical vein (UV), polytetrafluoroethylene (PTFE) and Dacron (DuPont, Wilmington, DE). Above-knee bypasses were performed in 181 patients: 77 were taking ASA and DIP at the time of operation, 41 were placed on postoperative "low-dose" warfarin, whereas 63 did not receive adjunctive medications. Late patency demonstrated no significant difference among the groups based on graft material used (SV 71%, UV 68%, PTFE 66%, and Dacron 65%) (P less than .25). Below-knee femoro-popliteal bypasses were performed in 183 patients: 82 were taking ASA and DIP at the time of operation, 40 were placed on warfarin postoperatively and no medications were given to 41 patients. Late patency rates (39 months) demonstrated that SV (62%) was superior to UV (51%), PTFE (30%), and Dacron (18%) (P less than .01). Femorotibial-peroneal bypasses were done in 42 patients: 13 patients were taking ASA and DIP at operation, 21 were placed on warfarin postoperatively and 8 received no medication. SV late patency (33 months) was again superior (43%) to UV (31%); no PTFE or Dacron grafts functioned after 24 months. Patients who took warfarin and ASA had the best early (16 months) patency results. Above-knee prosthetic grafts achieved late patency rates similar to SV while reducing operative time, shortening recuperation, and sparing the saphenous vein for use in the coronary or infrapopliteal vessels. In below-knee bypasses SV was superior to prosthetic grafts, with or without the use of ASA and DIP or warfarin.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of engineering complementary charged residues into the hydrophobic subunit interface of tyrosyl-tRNA synthetase. Appendix: Kinetic analysis of dimeric enzymes that reversibly dissociate into inactive subunits

Wild-type tyrosyl-tRNA synthetase (TyrTS) from Bacillus stearothermophilus is a symmetrical dimer. Four different heterodimeric enzymes have been produced by site-directed mutagenesis at the subunit interface so that the monomers are linked by a potential salt bridge in a hydrophobic environment. The two Phe-164 residues of wild-type TyrTS are on the axis of symmetry and interact in a hydrophobic region of the subunit interface. Mutation of Phe-164 to aspartate or glutamate in full-length TyrTS and to lysine or arginine in an active truncated enzyme (delta TyrTS) induces reversible dissociation of the enzyme into inactive monomers. Mixing mutants in equimolar amounts produces four different heterodimers: TyrTS(Asp-164)-delta TyrTS(Lys-164); TyrTS(Asp-164)-delta TyrTS(Arg-164); TyrTS(Glu-164)-delta TyrTS(Lys-164); TyrTS(Glu-164)-delta TyrTS(Arg-164). A general method is derived for analyzing the kinetics of dimeric enzymes that reversibly dissociate into inactive subunits. Application to mutants of TyrTS allows estimation of dissociation constants (Kd values) for the dimers. At pH 7.8, the heterodimers have Kd values of 6-14 microM, whereas for homodimers Kd = 120-4000 microM. These values decrease to about 30 microM for homodimers of TyrTS(Asp-164), TyrTS(Glu-164), and delta TyrTS(Lys-164) when the pH favors uncharged forms of the side chains at position 164. Each of the four salt bridges engineered into the hydrophobic subunit interface of TyrTS appears, therefore, to be weak. These engineered salt bridges may be compared with naturally occurring ones. In the latter, there are complementary interactions between the charges in the salt bridge with polar groups in the protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular characterization of Mycoplasma genitalium species-specific and cross-reactive determinants: identification of an immunodominant protein of M. genitalium

Species-specific proteins of Mycoplasma genitalium as well as proteins cross-reactive with M. pneumoniae have been identified using monoclonal antibodies generated against these mycoplasmas in enzyme-linked immunosorbent assays (ELISA) and Western blot analyses. Specificity of the antibodies was examined using M. hominis, M. orale M. salivarium and Acholeplasma laidlawii. A 140-kDa (kilodalton) protein of M. genitalium that appeared to be immunodominant in mice was also shown by radioimmunoprecipitation to be immunodominant in experimentally infected chimpanzees.