Meningococcal disease in childhood--a regional study in Ireland

A retrospective study of microbiology laboratory records of culture-confirmed cases of meningococcal disease in children under 14 years of age, admitted to four Dublin hospitals, was conducted for the period 1981-1991 inclusive. The study aimed to describe the epidemiology of meningococcal disease in childhood and to assess the potential of meningococcal group A and C vaccine in preventing disease. There were 406 cases of meningococcal disease of which 319 (78.6%) were in children under 5 years of age. The meningitis to septicaemia ratio was almost 4:1 (320 vs. 86 cases). Of the 406 cases, 216 (53.2%) cases occurred during the period November to March. The age-specific annual incidence rates for the Eastern Health Board region served was 64.2 per 100,000 under 1 year of age and 24.6 per 100,000 under 5 years of age. A relative increase in disease caused by meningococcal serogroup C was observed during the period of the study. Only 15% all cases could have been prevented by a policy of universal meningococcal group A and C immunisation at 2 years of age. Such a policy, therefore, is not recommended. A vaccine for preventing disease caused by meningococcal group B is urgently required.

An expression based clonality assay at the human androgen receptor locus (HUMARA) on chromosome X

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Mourning: a concern for medical-surgical nurses

Medical-surgical nurses working in a variety of settings with dying patients and their families play an important role in facilitating grieving. They can do much to help dying patients have a more peaceful death by listening to them. They can facilitate healing among families prior to death. They can help surviving family members begin a more healthy pattern of mourning. The tasks of mourning offer a useful guide for responding to the needs of the bereaved from a variety of cultural perspectives. Nurses can gain a greater sense of satisfaction in working with dying patients and grieving survivors by incorporating this framework into their practice.

Association among serum lipid and lipoprotein concentrations and physical activity, physical fitness, and body composition in young children

OBJECTIVE

To examine the relationships among indicators of physical activity, physical fitness, and body composition with serum lipid and lipoprotein levels in young children.

DESIGN

Cross-sectional and 1-year prospective cohort.

SETTING

Studies of Child Activity and Nutrition (SCAN) program, Galveston, Tex.

SUBJECTS

One hundred twenty-three 4- or 5-year-old black, Hispanic (of Mexican origin), and white children.

MEASUREMENTS

Body composition, resting heart rate, and cardiovascular fitness variables and serum lipid and lipoprotein levels were measured at age 3 or 4 years (study year 1) and at age 4 or 5 years (study year 2), and day-long heart rate was measured and the Children's Activity Rating Scale was administered between study years 1 and 2.

RESULTS

Year-1 waist/hip ratios were inversely correlated with total serum cholesterol (TSC) and low-density lipoprotein (LDL) levels. Mean activity level was inversely correlated with waist/hip ratios. On the basis of multiple regression analysis, the sum of seven skin-fold measurements, height, and gender explained 15.4% of the variation in triglyceride levels. The sum of seven skin-fold measurements was inversely correlated with the high-density lipoprotein (HDL) level. Resting heart rate, waist/hip ratio, and the slope of the exercise heart rate during fitness testing explained 19.5% of the variation in the concentration of an HDL subclass, HDL2. These children's levels of physical activity were associated with higher fitness levels. Year-1 waist/hip ratios and year-2 sum of seven skin-fold measurements were positively correlated with the LDL/HDL and TSC/HDL ratios.

CONCLUSION

Higher levels of cardiovascular fitness and lower levels of fatness were associated with more favorable serum lipid and lipoprotein levels in these young children. Physical activity appeared to have an indirect association with serum lipid and lipoprotein values through its relationship with higher fitness levels and lower levels of fatness.

Preparation of a cell-free translation system with minimal loss of initiation factor eIF-2/eIF-2B activity

Cell-free translation systems prepared from suspension-cultured HeLa S3 cells or mouse L cells by hypotonic shock followed by Dounce homogenization poorly initiated the translation of exogenous mRNA. In contrast, cell extracts prepared from cells exposed to the detergent lysolecithin translated exogenous mRNA readily. The block in initiation in the former lysates was localized to the ribosome fraction. During in vitro translation polysomes from homogenized cells disaggregated but the run-off ribosomes were unable to reinitiate translation. The block resulted from a decrease in eukaryotic initiation factor 2 (eIF-2) or the guanine nucleotide exchange factor (eIF-2B) activity, since the addition of eIF-2 or eIF-2B to these latter extracts substantially improved the capacity of the extract to initiate translation of exogenous mRNA. Extracts from homogenized cells, but not from detergent-treated cells, showed enhanced ability to phosphorylate the alpha subunit of exogenous eIF-2. We show that the method of cell extract preparation greatly influences the state of eIF-2/eIF-2B activity in the resulting extract and that extracts in which this activity is maintained can readily initiate translation on exogenous mRNA and reinitiate on endogenous mRNA.

Alpha-helical distorting substitution disrupt coupling between m3 muscarinic receptor and G proteins

Acetylcholine stimulation of the m3 or m2 muscarinic receptor expressed in Xenopus laevis oocytes induces either a fast transient or slowly oscillating calcium-sensitive chloride current. The speed of these currents reflects the efficiency of receptor coupling to guanine nucleotide-binding proteins and phosphatidylinositol (PI) turnover. Point mutations of the m3 receptor were made in a region of the third cytoplasmic loop to test whether receptor function relied on an alpha-helical structure of the G protein-coupling domain. Proline substitution for glutamate at position 257 disrupted the m3 response. Also, single alanine insertions between residues 259 and 260 disrupted the m3 receptor-stimulated response while double alanine insertions at this site had no effect. Based on these results, we suggest that a region of the third cytoplasmic loop of the m3 receptor possesses an amphipathic alpha-helical conformation.

Translation of equine infectious anemia virus bicistronic tat-rev mRNA requires leaky ribosome scanning of the tat CTG initiation codon

We have examined the translational regulation of the equine infectious anemia virus (EIAV) bicistronic tat-rev mRNA. Site-directed mutagenesis of the tat leader region followed by expression of the tat-rev cDNA both in vitro and in transiently transfected cells established that tat translation is initiated exclusively at a CTG codon. Increasing the efficiency of tat translation by altering the CTG initiator to ATG resulted in a dramatic decrease in translation of the downstream (rev) cistron, indicating that leaky scanning of the tat CTG initiation codon permitted translation of the downstream rev cistron. Since the tat leader sequences precede the major EIAV splice donor and are therefore present at the 5' termini of both spliced and unspliced viral mRNAs, the expression of all EIAV structural and regulatory proteins is dependent on leaky scanning of the tat initiator.

Proinsulin processing by the subtilisin-related proprotein convertases furin, PC2, and PC3

Experiments using recombinant vaccinia viruses expressing rat proinsulin I coinfected into COS-7 cells with recombinant vaccinia virus expressing human furin, human PC2, mouse PC3 (subtilisin-related proprotein convertases 1-3, respectively), or yeast Kex2 indicate that in this system both Kex2 and furin produce mature insulin, whereas PC2 selectively cleaves proinsulin at the C-peptide-A-chain junction. This is a property consistent with its probable identity with the rat insulinoma granule type II proinsulin processing activity as described by Davidson et al. [Davidson, H. W., Rhodes, C. J. & Hutton, J. C. (1988) Nature (London) 333, 93-96]. PC3 generates mature insulin but cleaves preferentially at the proinsulin B-chain-C-peptide junction. This pattern of cleavage by PC3 is similar, but not identical, to that of the highly B-chain-C-peptide junction-selective type I activity as described by Davidson et al., perhaps due to the presence of a P4 arginine residue near the C-peptide-A-chain junction unique to the rat proinsulins. These results along with data presented on the expression of both PC2 and PC3 in islet beta cells strongly support the conclusion that these proteases are involved in the conversion of proinsulin to insulin in vivo.

Activation of lipoprotein lipase in cardiac myocytes by glycosylation requires trimming of glucose residues in the endoplasmic reticulum

Incubation of cycloheximide-treated cardiac myocytes results in a time-dependent increase in cellular and heparin-releasable lipoprotein lipase (LPL) activities. N-Methyldeoxynojirimycin (1 mM) and castanospermine (100 micrograms/ml), inhibitors of glucosidases in the endoplasmic reticulum (ER), prevented the increase in cellular LPL activity. The glucosidase inhibitors did not influence the synthesis or turnover of LPL protein. Therefore activation of LPL by glycosylation in cardiac myocytes requires the trimming of glucose residues in oligosaccharide chains by glucosidases of the ER.

Inhibition of myocardial lipoprotein lipase by U-57,908 (RHC 80267)

U-57,908 (RHC 80267) was shown to inhibit lipoprotein lipase (LPL) activity in cardiac myocytes from rat hearts; the concentrations required for inhibition to 50% of control activity were 1.1 microM and 2.5 microM for myocyte homogenates and a post-heparin medium preparation, respectively. The inhibition of LPL activity by U-57,908 was not changed when the concentration of the triolein substrate and apolipoprotein CII activator in the assay was reduced. The availability of U-57,908 as a potent and selective LPL inhibitor may provide a useful experimental approach in studies on lipoprotein metabolism.

Inhibition of human immunodeficiency virus type 1 Tat activity by coexpression of heterologous trans activators

We examined the mechanism of Tat-mediated trans activation through competition experiments employing Tat proteins of human immunodeficiency virus type 1 (HIV-1) and equine infectious anemia virus (EIAV). EIAV Tat, as well as chimeric EIAV/HIV-1 Tat proteins, inhibited HIV-1 Tat-mediated trans activation in a cell-type-dependent fashion. Furthermore, these proteins inhibited trans activation by Tat-bacteriophage R17 coat protein chimeras. Inhibition resulted from competition between activation domains of effectors and competitors for a limiting cellular cofactor. The context in which competitor activation domains were expressed contributed to the extent of inhibition. In transfected cells, EIAV Tat and all chimeric competitors were located primarily in the cytoplasm, whereas HIV-1 Tat was primarily located in the nucleus. These data are consistent with a model for trans activation in which the activation domain of Tat associates with and conveys a cellular factor to the transcription complex via the trans-acting-responsive element (TAR).

A minimal lentivirus Tat

Transcriptional regulatory mechanisms found in lentiviruses employ RNA enhancer elements called trans-activation responsive (TAR) elements. These nascent RNA stem-loops are cis-acting targets of virally encoded Tat effectors. Interactions between Tat and TAR increase the processivity of transcription complexes and lead to efficient copying of viral genomes. To study essential elements of this trans activation, peptide motifs from Tats of two distantly related lentiviruses, equine infectious anemia virus (EIAV) and human immunodeficiency virus type 1 (HIV-1), were fused to the coat protein of bacteriophage R17 and tested on the long terminal repeat of EIAV, where TAR was replaced by the R17 operator, the target of the coat protein. This independent RNA-tethering mechanism mapped activation domains of Tats from HIV-1 and EIAV to 47 and 15 amino acids and RNA-binding domains to 10 and 26 amino acids, respectively. Thus, a minimal lentivirus Tat consists of 25 amino acids, of which 15 modify viral transcription and 10 bind to the target RNA stem-loop.

Identification of lentivirus tat functional domains through generation of equine infectious anemia virus/human immunodeficiency virus type 1 tat gene chimeras

The structural regions that comprise the functional domains of lentivirus Tat proteins were examined. Chimeric tat genes and chimeric viral promoters were constructed between the distantly related human immunodeficiency virus type 1 (HIV-1) and equine infectious anemia virus (EIAV). These exchange experiments revealed that the EIAV Tat-responsive element recognition domain is formed by two distinct structural regions. Activation domains of both HIV-1 and EIAV Tat contain a conserved core element, but at least HIV-1 Tat requires the presence of additional structural regions. The interchangeable nature of Tat activation domains suggests that these domains act through a common or ubiquitous cellular transcription factor.

Treatment of cardiac myocytes with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate, forskolin or cholera toxin does not stimulate cellular or heparin-releasable lipoprotein lipase activities

Incubation of isolated cardiac myocytes with 500 microM-8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate (CPT-cAMP) or 100 microM-forskolin for 2 1/2 h did not increase the heparin-induced release of lipoprotein lipase (LPL) into the medium. When LPL activity in cardiac myocytes was depleted by treatment of rats with cycloheximide (2 mg/kg; 2.5 h) and inclusion of the protein-synthesis inhibitor in the isolation solutions, incubation with CPT-cAMP or forskolin did not influence the rate of repletion of LPL activity in cells or the recovery of heparin-releasable LPL activity. Although the administration of cholera toxin (0.5 mg/kg; 16-17 h) to rats increased LPL activity in a low-speed supernatant fraction from heparin-perfused hearts, LPL activity was not increased in cardiac myocytes from cholera-toxin-treated rat hearts, and the heparin-induced release of LPL was unchanged. Incubation of cultured ventricular myocytes with 1 microgram of cholera toxin/ml or 500 microM-CPT-cAMP for 24 h did not increase cellular LPL activity or LPL released into the culture medium after a 40 min incubation with heparin. Therefore interventions that stimulate adenylate cyclase activity (forskolin, cholera toxin) or incubation with CPT-cAMP do not increase cellular LPL activity or promote the translocation of LPL to a heparin-releasable fraction in cardiac myocytes.

Improved detection of the histamine receptor on human peripheral blood mononuclear cells by crosslinking using tritiated as compared with radioiodinated histamine

In order to detect histamine receptors on the surface of human peripheral blood mononuclear cells, the cells were incubated in the presence of radiolabelled histamine and then the bifunctional crosslinker disuccimidyl suberate was added in various concentrations. They were then solubilized with sodium dodecyl sulphate, boiled, reduced and the lysate separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both 3H and 125I-radiolabelled ligands bound to a 16 kDa band, to be defined although a much clearer and obviously unequivocal signal was obtained with 3H-labelled histamine. This molecule migrated with the same mass on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a 16 kDa subunit which had been purified on a histamine affinity column from Triton X-100 solubilized mononuclear cells, indicating it to be the ligand-binding subunit for the histamine receptor on these cells. For 3H, fluorography with Entensify was required to obtain an autoradiographic signal. Although 3H took much longer to give a signal than 125I, the considerable background, artefacts and heavy lane trailing seen with [125I] histamine were completely abrogated when [3H]histamine was used. In addition, the distinction between specific and nonspecific binding was more clearly seen using [3H]histamine. The modifications reported here which improve signal detection for 3H should encourage the use of tritiated ligands in radioreceptor crosslinking, particularly those of low molecular weight which might otherwise undergo steric modification due to iodination, this having the potential for interfering with receptor ligand binding.

Apolipoprotein VLDL-II inhibits lipolysis of triglyceride-rich lipoproteins in the laying hen

In the laying hen, very low density lipoprotein (VLDL) particles contain large amounts of apolipoprotein (apo)-VLDL-II in addition to apoB. These triglyceride-rich lipoproteins are transported from the liver primarily to growing oocytes. Since no appreciable hydrolysis of triglyceride occurs during this transport, we have investigated the possibility that apoVLDL-II functions as an inhibitor of lipoprotein lipase (LPL). The presence of LPL in chicken follicular granulosa cells was demonstrated by immunoblotting, and LPL activity with the usual in vitro characteristics could be measured in cultured granulosa cell extracts. ApoVLDL-II inhibited LPL activity in these extracts as well as in the post-heparin medium of rat cardiac myocytes. Half-maximal inhibition in both systems occurred at 40 micrograms/ml, a concentration that is one-tenth of the circulating apoVLDL-II in the laying hen. Much less inhibition was observed with reduced and alkylated apoVLDL-II and with apoA-I. We conclude that the presence of apoVLDL-II on laying hen VLDL ensures efficient delivery of triglyceride to the oocyte for subsequent use as energy source by the embryo.

The immunosuppressive action of FK506. In vitro induction of allogeneic unresponsiveness in human CTL precursors

FK506 is an unusually potent new immunosuppressive agent that inhibits T cell-mediated immunity in vivo and in vitro. In these studies we sought to further elucidate the immunosuppressive mechanism of action of FK506 on human allogeneic MLR-induced CTL activation. FK506 induced suppression of cell-mediated lympholysis by PBMC was optimal at 1-2-nM concentrations, if added at the initiation of 6 day CML cultures. The sensitivity to suppression decreased with time, and fully differentiated effectors were resistant to inhibition by FK506. Suppression of CML was not reversed by washing the cultures, adding exogenous IL-2, or restimulating with fresh cells. Pretreatment of unfractionated or adherent allogeneic PBMC with FK506 blocked the stimulating activity of these cells. Furthermore, addition of FK506-treated stimulator cells to cocultures containing untreated responder and stimulator cells resulted in suppression of CML. The inhibition in the cocultures was greatest if the FK506-pretreated cells were autologous to the original stimulator, suggesting a relative specificity in the suppression obtained under these conditions. These studies suggest that, in addition to suppressing the response of alloreactive CTL precursors, FK506 reduces the ability of irradiated allogeneic PBMC to induce CTL generation.

Effect of taxol on the heparin-induced secretion of lipoprotein lipase from cardiac myocytes

The heparin-induced secretion of LPL into the incubation medium of cardiac myocytes occurred in two phases: a rapid release (5-10 min), followed by a slower rate of release (10-60 min). Reducing the incubation temperature from 37 degrees C to 23 degrees C inhibited the slow phase of secretion, but had no effect on the rapid phase. Similarly, taxol, a microtubule-stabilizing drug, selectively reduced the slow phase of LPL release, without influencing the rapid release of LPL into the medium or cellular LPL activity. The rapid heparin-induced release of LPL probably occurs from sites that are at or near the cell surface, and so microtubules must participate in the intracellular transport of LPL from sites of synthesis and glycosylation to the surface binding sites. Heparin-releasable LPL could be resolved into two fractions by chromatography on con A-Sepharose; this pattern of elution was not affected by the prior treatment of cardiac myocytes with taxol.

Neurovisual outcome following proton radiation therapy

From February 1981 to January 1984, 20 patients with a tumor of the upper clivus received proton irradiation at the Harvard Cyclotron Laboratory. For 15 patients with known neurovisual status (including visual acuity, color vision, visual field, and fundus examinations) we obtained a cumulative dose-volume histogram (DVH) of the optic nerves (ON) and the optic chiasm. The prescribed tumor doses ranged from 66.6 to 74.4 Cobalt Gray Equivalent (CGE) with a daily fraction size of 1.8 to 2.1 CGE. CGE is used because modulated protons have an RBE of 1.1 compared to 60Co. The follow-up ranged from 30 to 68 months (median 52). Two patients developed, 10 and 36 months post irradiation, a progressive visual deterioration affecting both eyes. This was attributed to an ON and a chiasm injury in one patient and to bilateral ON injury in the other patient. In the first patient, the dose-volume analysis indicated that approximately half of the ON and of the chiasm had received 65 CGE and 55 CGE, respectively. In the second patient, it indicated that a quarter of the left ON (LON) had received 55 CGE whereas the dose to the right ON (RON) was significantly less. This patient had diabetes mellitus which may be a predisposing factor. From this study, a complication rate of 20% (1/5) is observed when a substantial portion of the ON is taken to 65 CGE, while it doesn't exceed 12.5% (2/16) and 7.5% (1/13) at 55 CGE for the ON and for the chiasm, respectively. This suggests a tolerance dose implying a 10% rate of major complications close to 55 CGE. When a tumor requires a high radiation-dose, the exclusion of these structures at 55 to 60 Gy is recommended.

Selective detection of human papilloma virus DNAs by specific synthetic DNA probes

Specific oligodeoxynucleotide probes ranging from 20 to 35 nucleotides were defined to differentiate each of the HPV1a, 5, 6b, 8, 11, 16, 18 and 33. They were chosen using computer programs developed to compare simultaneously several 8000 bp long DNA sequences. Sequences common to all and to specific groups of the HPV DNA were also selected. Specificity of 32P-labelled probes for HPV6b, 11, 16, 18 and 33 was demonstrated and the sensitivity of the assays was evaluated by filter hybridization with viral clones and with DNA from cervical tumor biopsies.

Isolation and characterization of a 50 kDa testosterone-binding protein from Pseudomonas testosteroni

A testosterone-binding protein (Mr = 50,500) has been isolated from the Gram-negative bacterium Pseudomonas testosteroni. The protein was partially purified by a combination of ion exchange chromatography and chromatofocusing. Final purification was achieved by electroelution of the 50 kDa protein from SDS-polyacrylamide gels. Following renaturation from a diluted solution of guanidine-HCl, specific binding of [3H]testosterone to the purified protein was observed. The native protein has a pI of 6.8. It appears to contain 428 amino acids, 39% of which are hydrophobic. There is only one cysteine residue. Both chymotrypsin and V8 protease were used to produce peptide maps of the protein for use in future identification. The first 10 amino acids situated at the N-terminal of the protein were Ser-Pro-Phe-Asp-Leu-Arg-Pro-Leu-Ser-Gly. Testosterone binding to the protein was saturable at approximately 3.8 nmol/mg protein; the binding constant was approximately 25 nM. Unlabelled testosterone, androstenedione, 5 alpha-dihydrotestosterone and 5 beta-dihydrotestosterone were able to compete for [3H]testosterone bound to the protein; 17 beta-estradiol also competed for [3H]testosterone but to a lesser degree. Neither progesterone nor desoxycorticosterone competed for the testosterone-binding site. Binding of testosterone to the protein was stable at pH's ranging from 5.5 to 9.0 and at various temperatures ranging from 4 to 30 degrees C. The protein was unable to metabolize testosterone in either the presence or absence of the cofactor NAD.

Eicosanoid synthesis in 7,12-dimethylbenz(a)anthracene-induced mammary carcinomas in Sprague-Dawley rats fed primrose oil, menhaden oil or corn oil diet

The comparative effects of high-fat diets (20%, w/w) on eicosanoid synthesis during mammary tumor promotion in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rats were studied using diets containing 20% primrose oil (PO), 20% menhaden oil (MO) or 20% corn oil (CO). Sprague-Dawley rats fed the PO or MO diet had 21% of 24% fewer adenocarcinomas, respectively, than rats fed the CO diet. Histologically (i.e., mitotic figures, inflammatory cell infiltration and necrosis), the CO-fed rats exhibited the highest frequency of changes within tumors. Plasma fatty acid composition was significantly altered by diet, reflecting the composition of the oils which were being fed. Only the plasma of PO-fed rats contained detectable levels of gamma-linolenic acid (GLA). Arachidonic acid (AA) levels were significantly higher (p less than 0.05) in PO-fed than in CO- or MO-fed rats. MO-fed rats had significantly higher levels of plasma palmitic acid, while palmitoleic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were detected only in MO-fed rats. As expected, linoleic acid (LA) and AA levels were lower (p less than 0.05) in the MO-fed rats than in PO- or CO-fed groups. The plasma of the CO-fed rats contained significantly higher levels of oleic acid. Eicosanoid synthesis in mammary carcinomas of rats fed the 20%-fat diets was 2-10 times higher than in mammary fat pads of control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of MR and CT in evaluating clival chordomas and chondrosarcomas

Sixteen chordomas and nine chondrosarcomas of the clivus were evaluated with CT and MR either before (22 cases) or after (three cases) treatment with proton beam irradiation. The ability of these imaging techniques to provide information necessary to direct patient treatment was studied. The tumor was detected and its gross margins were identified by both techniques in all instances. No reliable diagnostic features allowing differentiation between these two tumors were encountered. MR generally was superior in defining the exact position of the brainstem and optic chiasm relative to the tumor, and it frequently provided superior information about tumor extension into the nasopharynx and cavernous sinus. CT was always better than MR in demonstrating tumoral calcification and in defining the exact anatomy of bone destruction. MR was generally superior to CT in demonstrating the position of the cavernous internal carotid artery relative to the tumor and often provided superior visualization of the vertebral and basilar arteries. In cases in which bone-induced artifact obscured the interface between the neural axis and tumor in the CT image, or in which the tumor had suprasellar extension and was likely to compress the optic chiasm and tracts, MR was of great value in planning irradiation therapy. The high occurrence of clinically asymptomatic signal intensity alterations in the MR studies of previously treated patients appears to limit the differential diagnostic value of this information. Given its greater availability and lower cost, CT appears to be the technique of choice for routine follow-up of previously treated patients.

Intraoperative decisions based on angioscopy in peripheral vascular surgery

We describe the technique of intraoperative angioscopy for delineation of peripheral vascular anatomy. Angioscopes with outer diameters of 0.85-2.9 mm have been used during 86 peripheral vascular procedures. Angioscopic inspections were performed during 68 femoral popliteal bypasses, four aortofemoral bypass grafts, one abdominal aortic aneurysm, two extra anatomic axillary femoral bypass grafts, and 11 other vascular procedures. We obtained useful images in 73 of 86 procedures (85%), thereby yielding 118 angioscopic inspections (53 arteries, 37 anastomoses, and 28 vein grafts). Changes in intraoperative management based on angioscopic findings included revision of five of 37 (14%) anastomoses, deletion of four of 31 (13%) completion angiograms, revision of eight of 17 (47%) in situ venous valves, and repetition of thrombectomy in six of seven (86%) cases. In 22 of 73 (30%) peripheral angioscopies, potential causes of graft occlusion were recognized. Complications from intraoperative angioscopy have included one anastomotic flap from intimal disruption that required anastomotic revision. Three small flaps, possibly resulting from angioscopic trauma, were recognized but appeared to have no clinical significance. In conclusion, intraoperative angioscopy provides visual assessment of luminal patency and anastomotic anatomy. This assessment alters intraoperative procedures in some cases and cannot be obtained by angiography.

Endocrine function following high dose proton therapy for tumors of the upper clivus

The endocrine status of patients receiving proton radiation for tumors of the upper clivus was reviewed to evaluate the effect of high dose treatment on the pituitary gland. The fourteen patients had chordomas or low grade chondrosarcomas and were all treated by the same techniques. The median tumor dose was 69.7 Cobalt Gray Equivalent (CGE) with a range from 66.6 to 74.4 CGE. (CGE is used because modulated protons have an RBE of 1.1 compared to 60Co). The daily fraction size was 1.8-2.1 CGE. The median follow-up time is 48 months, ranging from 30 to 68 months. All treatments were planned using a computerized multi-dimensional system with the position of the pituitary outlined on the planning CT scan. Review of the dose distribution indicated that the dose to the pituitary ranged from 60.5 to 72.3 CGE, with a median of 67.6 CGE. One female patient had decreased thyroid and gonadotropin function at the time of diagnosis and has been on hormone replacement since that time. The other three females were all pre-menopausal at the time of radiotherapy. At this time four patients (3 males and 1 female) have developed endocrine abnormalities 14 to 45 months after irradiation. All four had evidence of hypothyroidism and two have also developed corticotropin deficiency. The three males had decreased testosterone levels; the female patient developed amenorrhea and hyperprolactinemia. All four are asymptomatic with ongoing hormone replacement.

Computed tomography in the evaluation of lymphoma of the uterine cervix

Primary involvement of the uterine cervix is a rare presentation of extranodal lymphoma. The clinical and computed tomography findings are described in four patients ranging from 23 to 74 years of age. All presented with vaginal bleeding. Computed tomography findings were similar to those of other primary pelvic neoplasms, with diffuse uterine enlargement and lobular contour alteration often mimicking fibroids. Lymphadenopathy was not observed in comparison to secondary lymphoma of the female genitalia. All patients had excisional biopsies. One patient had an initial TAH and BSO. Histology was varied with one case of large cell lymphoma, one of diffuse histiocytic, one of unclassifiable poorly differentiated lymphoma, and one of nodular poorly differentiated lymphocytic lymphoma that was finally classified as granulocytic sarcoma. Disease extent could be assessed by computed tomography and aided treatment planning. In conclusion, computed tomography was found to be useful in the evaluation of uterine lymphoma. Although the findings are not specific, the local tumor extent can be evaluated at the same time as other sites of potential involvement.

Secretion of lipoprotein lipase from myocardial cells isolated from adult rat hearts

Heparin (5 U/ml) induced the release of LPL into the incubation medium of cardiac myocytes isolated from adult rat hearts. The secretion of LPL occurred in two phases: a rapid release (5-10 min of incubation with heparin) that was independent of protein synthesis followed by a slower rate of release that was inhibited by cycloheximide. The rapid release of LPL induced by heparin likely occurs from sites that are at or near the cell surface. LPL secretion could also be stimulated by heparan sulfate and dermatan sulfate, but not by hyaluronic acid, chondroitin sulfate or keratan sulfate. Heparin-releasable LPL activity measured in short-term incubations represented a large fraction (40-50%) of the initial LPL activity associated with myocytes, but the fall in cellular LPL activity following heparin was less than the amount of LPL activity secreted into the incubation medium. This discrepancy was not due to latency of LPL in the pre-heparin cell homogenates, but in part could be due to a three-fold greater affinity of the heparin-released enzyme for substrate as compared to LPL in post-heparin myocyte homogenates.

The locations of collagens with different thermal stabilities in fibrils of bovine reticular dermis

The techniques of differential scanning calorimetry and electron microscopy were combined to locate collagens with different thermal stabilities in bovine dermis. When calfskin was heated at 1.25 degrees C/min, denatured cores developed in the fibrils at 65 degrees C, leaving native-banded sheaths. Coincident with the initiation of shrinkage and loss of molecular orientation at 68 degrees C, the sheaths of the fibrils began to be denatured at distributed sites along the fibrils. At 80 degrees C the collagen lost its organized fibrillar structure. When thermally labile crosslinks had been stabilized by reduction with borohydride, an endotherm lying above 66 degrees C was suppressed, with proportional lowering of the total enthalpy change, and a fibrous texture revealing a helical subfibrillar structure remained. The three populations of collagen are located in the same fibrils. One, located in the cores of the fibrils, is half denatured at 68 degrees C. Another, established by crosslinks, is competent to sustain the regular appearance of fibrils even after 56% of the collagen in them has been denatured. This population is located as sheaths at the peripheries of the collagen fibrils. A third, denaturing below 59 degrees C, is codistributed with one or both of the two others.

Studies on the molecular organization of rat insulin secretory granules

Secretory granule-enriched fractions prepared from isolated rat islets of Langerhans, previously labeled in culture for 18 h with [3H]leucine, have been lysed and separated into pH 5.4 soluble and insoluble fractions by zonal sucrose gradient centrifugation. A high proportion of both labeled and immunoreactive rat insulins I and II were recovered in the insoluble granule core fraction in the expected ratio of approximately 60/40, respectively. Essentially equivalent amounts of the rat C-peptides on a molar basis were recovered in the granule supernatant fractions. The proportion of labeled proinsulin in the granule core fraction was less than 2% relative to insulin, while the soluble fraction contained about 8%, which probably arose mainly from disrupted proinsulin-rich noncrystalline prosecretory vesicles. Electron microscopic examination of the granule core fraction revealed large numbers of well preserved crystalline cores exhibiting typical dimensions and regular internal spacings of normal mature rat beta-granule inclusions. These results provide direct biochemical evidence that the beta-granules are nonuniform in composition with the insulin contained mainly in a crystalline state in the electron-dense central inclusions while the C-peptide is dissolved in the fluid bathing the crystalline hormone. The significance of this structural organization of the beta-granule is discussed.

Effects of dietary primrose oil on mammary tumorigenesis induced by 7,12-dimethylbenz(a)anthracene

The mammary tumor-promoting effect of a high-fat diet containing 20% evening primrose oil (PO) was compared to that of a 20% corn oil (CO) diet. Mammary tumors were induced in female Sprague-Dawley rats using 10 mg (Study 1) and 5 mg (Study 2) 7,12-dimethylbenz(a)anthracene (DMBA). The 10 mg dose of DMBA gave a total mammary tumor incidence of 47% in rats fed the PO diet and 80% for those fed the CO diet. When only adenocarcinomas were counted, the malignant mammary tumor incidences were 41% in rats fed the PO diet and 73% in rats fed the CO diet. In a second study using 5 mg DMBA to induce mammary tumors, total tumor incidences were 50% for PO-fed rats and 63% for those receiving a CO diet. Again, when only adenocarcinomas were counted, tumor incidences were 27% for PO- and 63% for CO-dieted rats. Analysis of plasma fatty acid profiles indicated that animals fed a 20% PO diet showed significant increases in 18:3 and 20:4 fatty acids and significant decreases in 16:0 and 18:1 compared to animals fed a 20% CO diet. These results indicate that the mammary tumor promoting effect of a diet containing 20% fat can be diminished by substituting PO for CO. Moreover, the promoting effect on mammary cancer by a high-fat diet could be depressed by feeding a source of gamma-linolenic acid (GLA).

Short-term incubation of cardiac myocytes with isoprenaline has no effect on heparin-releasable or cellular lipoprotein lipase activity

Heparin (5 units/ml) produced a rapid (5-10 min) release of lipoprotein lipase (LPL) into the incubation medium of cardiac myocytes. Preincubation of myocytes for 30 min with 0.01-10 microM-isoprenaline, 100 microM-forskolin or 500 microM-8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate did not increase heparin-releasable LPL activity. Incubation with isoprenaline also did not change cellular LPL activity, even though the catecholamine did increase the phosphorylase a activity ratio.

The effect of the respiratory cycle on mediastinal and lung dimensions in Hodgkin's disease. Implications for radiotherapy gated to respiration

Changes in mediastinal and lung dimensions during respiration were studied to assess the potential of radiotherapy gated to respiration to minimize normal tissue irradiation. Twelve patients with mediastinal Hodgkin's disease were assessed using chest radiographs and thoracic computed tomography (CT) scans both during quiet breathing and at maximum inspiration in the standing, supine, and prone positions. A simple measure of the bulk of mediastinal disease, the ratio of the width of mediastinal mass to thoracic diameter, was determined from posteroanterior (PA) chest radiographs. The volumes of mediastinum, irradiated and protected lung if anteroposterior (AP) and PA mantle fields were used were determined from sequential thoracic CT scans and three-dimensional treatment planning and compared at quiet breathing and deep inspiration. The mediastinal width to thoracic diameter ratio decreased from quiet breathing to deep inspiration an average of 3%, 9%, and 11% for the standing, supine, and prone positions, respectively. Lung volumes as measured from the thoracic CT scans showed that on average, 8% more lung was protected at deep inspiration than at quiet breathing, independent of treatment position. The maximum increase in the percentage of protected lung from quiet breathing to deep inspiration was seen in patients with extensive mediastinal adenopathy suggesting that radiotherapy gated to respiration may be most advantageous in the subset of patients.

Empty-bladder (hysterographic) view on US for evaluation of intrauterine devices. Work in progress

Ultrasound scanning of the pelvis with an empty bladder permits a true frontal view of the uterus to be easily obtained. This view is comparable to the en face view seen at hysterography performed with contrast material. Good definition both of the endometrium and the uterine wall makes this the optimal method for the evaluation of an intrauterine contraceptive device.

Expression of endogenous retroviral envelope glycoprotein as a determinant of immunity to Rous sarcoma

To analyze the effect of the expression of endogenous retroviral envelope glycoprotein on tumor immunity, patterns of sarcoma growth were compared in inbred FP line chickens infected with either of two strains of avian sarcoma virus, Pr-B (subgroup B) or cl.85 (subgroup G). These viruses were chosen for analysis because the envelope glycoprotein of Pr-B, but not of cl.85, is antigenically cross-reactive with the endogenous retroviral envelope glycoprotein expressed in the FP line. Inoculation of 1-day-old hatchmates with either virus yielded a significant percentage of chickens with distal sarcomas localized to visceral organs. By contrast, a marked difference in the percentage of chickens bearing distal sarcomas was noted when sarcoma tissue excised from virus-inoculated donors was implanted in 1-day-old recipients; a high proportion of the recipients of Pr-B-induced sarcoma tissue (Pr-B-sarcoma recipients), but only a low proportion of the cl.85-sarcoma recipients, exhibited distal sarcomas. At 3 weeks posthatch, a significantly higher percentage of donor-derived cells was detected in the primary tumors of the cl.85- versus the Pr-B-sarcoma recipients. A model of immune control, premised on the tolerogenicity of endogenous viral glycoprotein, is proposed to rationalize these results.

Effect of selenium supplementation on selenium balance in the dependent elderly

Although trace minerals are necessary constituents of enzymes, dietary requirements of these nutrients for the elderly are unknown. This study measured selenium balance in six dependent elderly men before and after five weeks daily administration of 200 micrograms organically-bound selenium; dietary selenium intake averaged 62.1 +/- 7 micrograms/day during both study periods. Selenium status was assessed not only chemically but also biologically as red cell and platelet glutathione peroxidase activities. Plasma selenium averaged 8.8 +/- 0.8 micrograms% (normal: 10 +/- 2 micrograms %) when intake derived from dietary sources alone and increased during medicinal supplementation to an average of 12.8 +/- 1.9 micrograms %. The rise in plasma selenium was not associated with an increase in red cell or platelet glutathione peroxidase activity. The effect of selenium supplementation on in vivo platelet aggregability was studied by measuring plasma levels of beta-thromboglobulin and platelet factor 4, two proteins secreted concomitant with aggregation. beta-thromboglobulin diminished 7.5 +/- 11.0 ng/ml and platelet factor 7.6 +/- 11.0 ng/ml during selenium supplementation despite no change in platelet glutathione peroxidase activity. These data support the concept that selenium nutritional status should be assessed not only by blood selenium content but also by selenium-dependent enzyme activity or selenium-dependent biologic effect.

Delineation of peripheral and coronary detail by intraoperative angioscopy

In this study, the development of intraoperative angioscopy, the value of the information obtained, and the problems encountered with the procedure are reported. Eight angioscopes, 1.5 to 2.8 mm in diameter, with a line resolution of greater than 0.4 mm at 5 mm, were used. One-hundred ten angioscopic investigations were performed in 46 patients; 24 at peripheral bypass surgery and 22 at coronary artery bypass surgery. These included 68 arteries, 28 new anastomoses, six old grafts, five laser angioplasties, and three in situ vein grafts. The most important finding was that angioscopic data provide information not available from probes or angiography. Angioscopic findings were responsible for a change in surgical procedures in 12 patients (26%) including three anastomotic revisions, three alterations in graft site placement, and two repeat thrombectomies. The most significant technical problems were lack of steerability and insufficient irrigation, which resulted in poor angiographic images. Further technical development is necessary before routine intraoperative angioscopy is practical. Nevertheless, if these problems are resolved, angioscopy will provide unique, high-resolution information which can directly alter surgical therapy.

Pulsed ultraviolet lasers and the potential for safe laser angioplasty

Endoscopic laser ablation of atheroma using continuous wave lasers is limited by imprecise control of thermal ablation, resulting in a crater that expands in width and depth, with thermal damage to adjacent normal tissue. We compared the gross and histologic effects of pulsed 308 mm excimer irradiation to continuous-wave Nd:YAG and Argon Ion laser irradiation, and pulsed 1,060 nm, 532 nm, 355 nm, and 266 nm laser irradiation in 205 atherosclerotic aortic segments. In contrast to the continuous-wave Nd: YAG, Argon Ion, and pulsed 1,060 nm, 532 nm, and 355 nm laser irradiation, which produced gross and histologic evidence of uncontrolled ablation, the 308 nm and 266 nm pulsed lasers induced incisions that conformed precisely to the beam configuration without gross evidence of thermal injury. The incision edges from these two lasers were histologically smooth and comparable to a scalpel incision. Our histologic findings suggest that rapid, precise endoscopic ablation of vascular and nonvascular tissue can be performed at these shorter pulsed wavelengths with very high precision with relatively little damage or risk to adjacent tissue.

Xanthogranulomatous pyelonephritis in childhood

Eleven children with xanthogranulomatous pyelonephritis are reported. The left side was affected in all patients. It is suggested that the diagnosis can be made pre-operatively. The condition is characterised by the fact that it is always unilateral and that renal calculi are found in a kidney with gross impairment of function; associated anaemia, leucocytosis and raised ESR are also present. The cause is unclear, but an obstructive element with infection is usually found.