Nuptial and childbearing customs of the ethnic minorities in China

The current nuptial customs of the ethnic minorities in China are examined. "Although monogamous marriage has now been adopted by all but a few ethnic communities, variations still exist between different nationalities in the specific forms of marriage and range of intermarriage owing to the uneven nature of historical development. Such variations are shaped by various factors of the given locality and given time such as the socioeconomy, religion, culture and education, and exert direct influence on the childbearing behavior and reproduction of the ethnic population."

Prevention of invasive bacterial diseases by immunization with polysaccharide-protein conjugates

Covalent binding of CPS to T cell-dependent carrier proteins to form conjugates can be done by clinically acceptable methods. As a component of a conjugate, two immunologic properties of CPS are changed: 1) their immunogenicity is increased and; 2) reinjection induces a booster response in the young (T cell-dependence). Serum antibodies induced by the CPS alone, or as a component of a conjugate, are qualitatively similar: the difference between antibodies elicited by the CPS or the conjugate is quantitative. A clinical trial with a Hib-DT conjugate showed that conjugates could confer immunity in an age group not protected by the CPS alone. (table; see text) Induction of serum CPS antibodies confers protection against capsulated bacteria in the bloodstream: their role in the interaction of these pathogens on the mucous membranes has not been characterized. Preliminary in vitro experiments suggest that secretory antibodies to non-capsular structures may also exert protective immunity.

DNA gyrase binds to the family of prokaryotic repetitive extragenic palindromic sequences

A family of repetitive extragenic palindromic (REP) sequences is composed of hundreds of copies distributed throughout the chromosome. Their palindromic nature and conservation suggested that they are specifically recognized by a protein(s). We have identified DNA gyrase [DNA topoisomerase (ATP-hydrolysing), EC 5.99.1.3] as one of the REP-binding proteins. Gyrase has at least a 10-fold higher affinity for DNA containing REP sequences than for DNA not containing REP sequences. Binding effectiveness correlates directly with the number of REP sequences in the DNA. DNase I footprinting shows that gyrase protects 205 base pairs on a REP-containing DNA fragment enclosing the REP sequences. In agreement with the above results, a comparison of the REP consensus sequence with the sequence of previously identified pBR322 "strong" gyrase cleavage sites reveals a high degree of homology. Because REP sequences are numerous and found throughout the genome, we suggest they have physiological functions mediated through their interaction with gyrase, such as being sites of action for the maintenance of DNA supercoiling. In addition, we speculate that these interactions may be of a structural nature, such as involvement in the higher-order structure of the bacterial chromosome.

A new DNA immune adsorbent for hemoperfusion in SLE therapy: a clinical trial

This investigation studied the preparation and clinical trial of DNA immunoadsorbent for hemoperfusion in systemic lupus erythematosus (SLE) therapy. DNA was complexed with blue tetrazolium (BT), then mixed with collodion, and finally adsorbed on macroporous spherical polymeric adsorbent. The percentage of DNA thus immobilized was 98-98.5%, and no release was detected during hemoperfusion. A patient with severe SLE was treated with the above adsorbent in hemoperfusion. The patient was in coma, with high anti-DNA antibody and abnormal immune complex levels, which fell sharply from 56.34% to 0.8% after 2.5 h of whole-blood hemo perfusion. There were no major clinical complications, and 2 weeks later, her proteinuria level became normal and immune complex levels were sustained. She was then discharged from the hospital and has been in good health for more than 1 year.

Experimental study of morphological changes after gastroplasty

Twelve rabbits were sacrificed one and three days, one, two, four and eight weeks after horizontal gastroplasty in order to investigate morphological changes after operation. Histology of the proximal pouch of the stomach showed various degrees of mucosal damage and a close relationship between its severity and high pH of the pouch. This suggested the usefulness of pH measurement of the gastric juice in the proximal pouch as an indicator of mucosal damage after gastroplasty.

Activity of temocillin and other penicillins against beta-lactamase-inducible and -stably derepressed enterobacteria

MICs of temocillin, carbenicillin, ticarcillin, mezlocillin, piperacillin and ampicillin were determined for mutant series of Enterobacter cloacae, Citrobacter freundii, Proteus vulgaris, Morganella morganii and Serratia marcescens with inducible, stably derepressed or basal expression of chromosomal Class I beta-lactamases. Ampicillin was inactive (MIC greater than 256 mg/l) both against beta-lactamase-inducible organisms (except C. freundii) and their stably derepressed mutants, whereas basal mutants were sensitive (MIC 2-8 mg/l). Carbenicillin, ticarcillin, mezlocillin, piperacillin (and ampicillin for C. freundii) were active against both inducible and basal organisms (MIC less than 16 mg/l), but inactive against the derepressed mutants (MICs usually greater than 64 mg/l). Temocillin inhibited all the organisms, including the stably derepressed mutants, at 16 mg/l. Derepressed S. marcescens, M. morganii and Pr. vulgaris were as susceptible as the inducible strains and basal mutants. MICs of temocillin for derepressed mutants of E. cloacae and C. freundii were 4-16 fold above those for their inducible parent strains, but remained within the clinical range.

Development of neutralizing antibodies and group A common antibodies against natural infections with human rotavirus

We determined the levels of group A common and neutralizing antibodies against human rotavirus in paired serum specimens obtained from 38 infants within 12 days of the onset of diarrhea. Thirty of the infants excreted rotavirus in stools, and eight did not. Nine patients (30%) with rotavirus diarrhea and seven patients (88%) with diarrhea due to other causes had detectable levels (greater than or equal to 1: 80) of immunoglobulin (IgG) common antibodies in acute-phase sera. All the patients with rotavirus diarrhea showed at least fourfold rises in titers of IgG or IgM common antibodies or both, while only two control patients showed significant rises in either IgG or IgM common antibodies in their convalescent-phase sera. Of the 19 patients excreting "short" electropherotypes of rotavirus, 18 showed at least fourfold rises in titers of neutralizing antibodies against serotype 2 human rotavirus but not against serotype 1, 3, or 4. Nine of the ten patients excreting "long" electropherotypes showed significant rises in neutralizing antibodies against serotype 3, and the other patient showed a significant rise in neutralizing antibodies against serotype 1. One patient excreted long and short electropherotypes simultaneously, and he also showed a significant rise in neutralizing antibodies against serotype 2 and 3 viruses. The control patients with diarrhea did not show significant changes in titers of antibodies against any of the serotypes. These results demonstrated that the neutralizing antibody response within 2 weeks after clinical onset is specific for the infecting serotype of rotavirus.

Healing of the resected liver stump: its process and the significance of portal blood flow

In an effort to investigate the healing process of resected liver stump and the significance of portal and hepatic arterial flow. In addition to hepatectomy in the first group, an arterial and a portal branch were ligated in the second and third groups, respectively. It was demonstrated that portal branch ligation influenced a delay in healing of resected liver stump rather than hepatic arterial branch ligation. It is assumed that portal blood flow is more responsible for liver stump healing as well as hepatic regeneration than is hepatic arterial flow.

Clinical and immunologic responses to the capsular polysaccharide of Haemophilus influenzae type b alone or conjugated to tetanus toxoid in 18- to 23-month-old children

The safety and immunogenicity of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) alone, or covalently bound to tetanus toxoid in saline solution (Hib-TT) or adsorbed onto AI(OH)3 (Hib-TT ads), were evaluated after one injection into 18- to 23-month-old healthy children in Sweden. No side reactions were elicited by Hib CPS; side reactions elicited by the two conjugates were similar and comparable to those reported for diphtheria and tetanus toxoids adsorbed. Hib-TT was the most immunogenic of the three vaccines, eliciting about 10-fold higher antibody levels than Hib CPS; of 28 vaccinees, all had greater than 1.0 microgram Ab/mL serum after immunization with Hib-TT. Increases of Hib CPS antibodies within immunoglobulin classes induced by the three vaccines were, in decreasing order, IgG greater than IgM greater than IgA. Within IgG subclasses, rises in IgG1 Hib CPS antibodies were the most frequent, followed by IgG2; some vaccinees with high postimmunization levels also had rises in IgG3 and one in IgG4. Immunization-induced Hib CPS antibodies were bactericidal. Hib-TT also elicited higher levels of tetanus toxoid antibodies than Hib-TT ads; these tetanus toxoid antibodies neutralized tetanus toxin in vivo.

Effects of argon laser on vascular materials

The laser has been shown to vaporize arterial atheromatous plaque, but little information is available about its effect on various vascular materials. This study attempts to determine a safe margin for laser graft thrombectomy. An 18 watt argon laser with a 2 mm metal-encased sapphire tip fiberoptic system was used. Specimens such as autogenous vein, polytetrafluoroethylene (PTFE), and Dacron grafts as well as polypropylene and PTFE sutures were harvested from amputated human legs. Laser energy was delivered from the tip of the fiberoptic system while perpendicular to and in direct contact with these materials. The effects were examined histologically and compared by determining the bursting pressure of the grafts and the breaking strength of the sutures. The results indicate that seven sections of autogenous vein grafts and 11 sections of PTFE grafts were perforated by laser delivery of 32.9 +/- 9.9 and 50.0 +/- 7.1 joules, respectively, whereas two sections of Dacron grafts were easily perforated after only 10 joules was delivered. The bursting pressure of PTFE and autogenous vein grafts after laser application was determined to be more than 300 mm Hg. The breaking strength of 6-0 PTFE sutures was compared before and after receiving 200 joules by contact laser application. No significant difference was found; in a before laser application the breaking strength was 585.0 +/- 9.6 gm compared with 560.0 +/- 16.4 gm after laser application (n = 4, p greater than 0.1). However, 6-0 polypropylene sutures were easily melted after receiving 10 joules of laser energy.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative hemostasis and wound healing in intestinal anastomoses using the ILA stapling device

Intraoperative hemostasis and wound healing of 24 side-to-side intestinal anastomoses constructed with the ILA stapling device were studied in 12 dogs by comparing the ILA-32 and ILA-52 staple cartridges. Hemostasis was evaluated by intraoperative measurement of blood loss and bleeding time at the staple line. There was no statistically significant difference in mean blood loss (p greater than 0.05) or mean bleeding time (p greater than 0.10) between the two cartridges. Wound healing was studied using bursting strength measurements and silicone rubber casting of the microvasculature at the staple line. At 3 days, 1 week, and 2 weeks postoperatively, there was no significant difference between bursting strength values achieved with the two cartridges. Microscopic examination revealed that wound healing in the ILA-52 anastomoses lagged behind healing in the ILA-32 anastomoses at each postoperative time period studied. The silicone rubber casting study showed a paucity of microvasculature at the healing staple line with the ILA-52 cartridge as compared with the ILA-32 cartridge. Our findings suggest that the ILA-52 cartridge does not offer significantly improved intraoperative hemostasis over the ILA-32 cartridge and may affect the microvasculature at the staple line in a way that delays wound healing.

Laser angioplasty

Clinical trials for Argon Laser angioplasty of patients with severe ischemia of the lower extremities are presented. All instances were limited to those in whom no conventional reconstructive operation was ideal. Laser angioplasty proved to be beneficial when used in conjunction with standard vascular surgical procedures under appropriate conditions. The short term evaluation was favorable; however, a long term study must be followed and completed prior to routine use of laser angioplasty.

Involvement of a nucleolar component, perichromonucleolin, in the condensation and decondensation of chromosomes

A component of the nucleolar material, perichromonucleolin (PCN), was identified by a specific antiserum against nucleoli obtained from a scleroderma patient. The distribution and changes of PCN during the mitotic cycle were followed using this antiserum and indirect immunofluorescence microscopy. Based upon the behavior of PCN during mitosis, it could be differentiated into chromosomal and nonchromosomal portions. During prophase the former gradually associates with the surface of the condensing chromosomes and forms the coat or pellicle around the metaphase and anaphase chromosomes. This pellicle PCN is carried by the anaphase chromosomes to the daughter nuclei. During the time from telophase to interphase, the pellicle PCN dissociates from the decondensing chromosomes and is incorporated into the new nucleoli. The nonchromosomal PCN, after the breakdown of the nuclear membrane, distributes in the cytoplasmic region around the condensed chromosomes and diffuses into the cytoplasm during anaphase. Preliminary biochemical analysis by immunoblotting showed that the PCN consists of two main proteins with molecular masses of 36 kDa and 30 kDa.

Direct vision valvulotomy in in situ venous bypass

The autogenous saphenous venous bypass is accepted as an optimal procedure for distal arterial reconstruction. However, serious complications, including incomplete valvulotomy, laceration of the venous wall and persistent arteriovenous communications, are found in in situ bypasses. To avoid these complications, a new and simple technique using an angioscope in the in situ venous bypass has been developed. Angioscopy prevents tearing of the vein wall and avoids inaccurate incision of the valves.

Direct vision valvulotomy for nonreversed vein graft

A new and easy technique using an angioscope in a nonreversed, isolated vein bypass is suggested herein. Direct vision valvulotomy with an angioscope in nonreversed vein graft saves operating time, prevents tearing of the vein wall and inaccurate incision of the valves.

Phospholipid methylation in canine myocardium: kinetic characteristics and the effect of endotoxin administration

The kinetic characteristics and the effect of endotoxin administration on the enzymatic methylation of phospholipids in dog heart microsomes were studied using S-adenosyl-L-[methyl-3H]methionine as a methyl donor. Kinetic studies in control dogs reveal that the stepwise methylation of phosphatidylethanolamine to phosphatidylcholine was catalyzed by three different enzymes. Methyltransferase I catalyzed the methylation of phosphatidylethanolamine to phosphatidyl-N-monomethylethanolamine, had a very low Km (approximately 1.5 microM) for S-adenosylmethionine, and a pH optimum of 6.5, and it was stimulated by Mg2+ and Ca2+. Methyltransferase II catalyzed the methylation of phosphatidyl-N-monomethylethanolamine to phosphatidyl-N,N-dimethylethanolamine, had a low Km (8-12 microM) for S-adenosylmethionine, and a pH optimum of 8.5, and it was stimulated by low concentrations (less than 1 mM) of Ca2+ but was unaffected by Mg2+. Methyltransferase III catalyzed the formation of phosphatidylcholine from phosphatidyl-N,N-dimethylethanolamine, had a high Km (approximately 33 microM) for S-adenosylmethionine, and a pH optimum of 9.5, and it was unaffected by Mg2+ or Ca2+. Experiments with trypsin digestion indicate that methyltransferases I and III were partially embedded while methyltransferase II was completely exposed to the surface of the membrane. Endotoxin administration (2 and 4 hr) decreased the Km and Vmax by 30 to 36% and 24 to 37.7%, respectively, for S-adenosylmethionine. Since the enzymatic methylation of phospholipids has been implicated to play an important role in the regulation of membrane structure and function, the endotoxin-induced decreases in the Km and Vmax of phospholipid-methylating enzymes in dog heart microsomes may contribute to the development of myocardial dysfunction in endotoxin shock.

Thermolabile proton translocating ATPase and pump activities in a clathrin-coated vesicle fraction from an acidification defective Chinese hamster cell line

We have recently described a mutant of Chinese hamster ovary cells, termed G.7.1, that contains a temperature-sensitive, conditionally lethal mutation resulting in defective vacuolar acidification (Marnell, M. H., Mathis, L. S., Stookey, M., Shia, S.-P., Stone, D.K., and Draper, R. K. (1984) J. Cell Biol. 99, 1907-1916). To further characterize the lesion, clathrin-coated vesicles were partially purified from wild type and G.7.1 cells, and the thermolabilities of vanadate and oligomycin-insensitive, N-ethylmaleimide-sensitive, H+-ATPase activity, 32Pi-ATPase exchange activity, and proton pumping were compared. All three parameters of H+ pump activity were markedly diminished by preincubation at 44 degrees C for vesicles harvested from the G.7.1 cells, but not for those from wild type cells. Phosphatidylserine did not protect against heat inactivation in vesicle fractions prepared from G.7.1 cells. The results suggest that the mutation responsible for defective acidification in G.7.1 cells is expressed at the level of the proton pump of organelles present in our clathrin-coated vesicle-enriched preparation.

Argon laser angioplasty with a laser probe

A preliminary basic study of argon laser angioplasty with the use of a specially designed probe is presented. Arterial specimens were harvested from 10 amputated lower extremities. The studies included the evaluation of coaxial laser angioplasty in 10 partially or totally occluded arteries; the observation of the effect of perpendicularly applied laser energy on 35 thrombi, 54 soft and 10 hard atherosclerotic, and 51 normal arterial walls; the comparison of laser energy requirements for coaxial vessel lumen enlargement or recanalization vs. perpendicular penetration in 10 occluded, hard atherosclerotic arteries; and the spectrographic analysis of calcium density gradient in two specimens. The results showed that the power required for vessel lumen enlargement was 10 +/- 6 J/mm of atherosclerotic vessel (mean +/- standard deviation). The probe followed the original arterial lumen, did not perforate the vessel wall, and created a smooth, enlarged path. The power required to penetrate perpendicularly to a similar depth for thrombi, soft and hard atherosclerotic plaques, and normal arterial walls was 15 +/- 4, 30 +/- 15, 65 +/- 32, and 246 +/- 123 J/mm, respectively. In the hard calcified specimens, laser energy required for coaxial lumen enlargement or recanalization was significantly less than that for perpendicular penetration (p less than 0.05), which correlated with the calcium density map indicating an increase from inside to outside.

Intimal response of saphenous vein to intraluminal trauma by stimulated angioscopic insertion

Endothelial damage after simulated angioscopic insertion was evaluated in 22 dogs by radioimmunoassay of endogenous 6-keto-prostaglandin F1 alpha (stable product of prostacyclin produced by the endothelium) by means of a closed perfusion system and scanning electron microscopy. In 20 dogs, a 1.7 mm diameter polyethylene tube similar in size and physical characteristics to a commercially available angioscope was passed once into the distal venotomy site and out of the proximal venotomy site for a total distance of 15 cm in the left saphenous vein (group A) and 10 times in both directions in the right saphenous vein, destroying all valves (group B). The vein segments were examined immediately after simulated angioscopic insertion and at intervals of 2, 3, and 4 weeks. The remaining two dogs were used as control animals to establish baseline prostacyclin production. All veins were patent when harvested. Scanning electron microscopy revealed globular and contracted endothelial cells in some areas of group A veins, whereas partial longitudinal absence of endothelial cells was noted in group B veins. Intimal coverage was complete by 2 weeks in group A veins and between 3 and 4 weeks in group B veins. Prostacyclin synthesis of group B veins was significantly less than that of group A at day 1 and at 2 weeks after operation (p less than 0.05), reaching that of control vein synthesis by 4 weeks. This study suggests that simulated angioscopic trauma of the luminal surface of the canine saphenous vein had no negative effect on early patency.

Role of enteric plexuses in the competency of telescoped intestinal valves

The mechanism of preventing intestinal regurgitation by means of a telescoped intestinal valve has been investigated in this study. Ten telescoped intestinal valves were uniformly created in dogs. A tolerance test to barium reflux was performed before the animals were sacrificed 16 weeks postoperatively, which yielded various barium tolerance values. Statistical analysis revealed that the differences in barium tolerance values in the uniformly constructed valves were closely related to the proportion of the enteric plexuses which contained ganglion cells with normal shapes (r = 0.97, p less than 0.001) and their intestinal segment coverage (r = 0.94, p less than 0.001), but no correlation was found between barium tolerance and the thickness of the valvular musculature (r = 0.04) or the length of the artificial valve (r = 0.39). The results in this study suggest that the intact enteric plexuses play an important role in modulating the competency of the telescoped intestinal valve.

Use of intragastric balloons for weight reduction. An experimental study

The effect of intragastric balloons as a noninvasive method for weight reduction was observed in nine castrated Yorkshire pigs. None of the animals lost weight. The appetites of the experimental animals were inhibited for only a short period of time. A significant dilatation of the stomach after balloon insertion was noted which resulted from increased food intake and obliterated the effect of the intragastric balloons. A long-standing lower blood glucose level played an important role in the increments in food intake and dilatation of the stomach. At the same time, ulceration was seen in 83.3 percent of the animals that received balloons. We conclude that intragastric balloon therapy may not be an effective approach for managing morbid obesity in human subjects.

Relationships between ionizing radiation, bone marrow transplantation and leukemogenesis

Studies of the relationships between ionizing radiation, bone marrow transplantation and leukemogenesis were carried out in 343 LACA mice. The recipients (female) were given whole-body irradiation with 7 or 8 Gy of Co-60 gamma-rays, while the donors (male) were given whole-body irradiation with 3, 1.5, 0.5, 0.1, 0.05 and 0 Gy of Co-60 gamma-rays. Each recipient was intravenously infused with 1-3 X 10(7) of the mixed marrow cells of donors. In the result, the average incidence of surviving over 1 month was 86% in the recipients. Myelocytic leukemia developed in all the transplanted groups, the average incidence being 88.5%. Leukemia was observed in 1.5-2.5 months after transplantation in the recipients receiving marrow cells from donors exposed to 3 Gy, but in 5-8 months in other groups. It was demonstrated by the analysis of Y-chromosome that the leukemic cells were derived from the donor's marrow cells. The results suggest that marrow transplantation for the mice irradiated by Co-60 gamma-rays of lethal dose can protect them from death, but promote the development of leukemia. Radiation can induce production of factors which lead to leukemic transformation of engrafted normal marrow cells in the irradiated mice; the direct damage of DNA caused by radiation is not the unique factor that gives rise to leukemia.

Patterns of pannus growth of the expanded polytetrafluoroethylene vascular graft with special attention to the intimal hyperplasia formation

Serial histologic observations of the healing process of expanded polytetrafluoroethylene (PTFE) vascular grafts in dogs were performed. The common iliac arteries of 12 mongrel dogs were replaced with a 2-cm segment of 6 mm PTFE graft, bilaterally. The grafts were studied microscopically after the animals were killed at 4, 8, 12, 16, 20, and 24 weeks. All the grafts remained patent up to 24 weeks. Special attention was paid to the histological characteristics of pannus growth, which were divided into two types: smooth appearing and irregular. The former type was characterized by smooth, thinner connective tissue growth along the graft, and the latter was defined as irregular-shaped pannus containing large and small thrombi. Only pannus of the smooth type showed similar growth patterns and growth rates. These findings suggest essentially that pannus develops smoothly from both ends of the graft; however, thrombi disturbed this growth pattern. In 24 grafts, eight nodular lesions of the pannus (greater than 500 mu in height) were found: five distally and three proximally. All eight lesions were found within 3 mm of the anastomoses. Among these eight lesions, five were on the completely healed pannus, and the remainings were all on the irregular pannus. This suggests that thrombi organization followed by nodular lesions are major offending factors that lead to the formation of intimal hyperplasia.

The competence and bacteriologic effect of the telescoped intestinal valve after small bowel resection

In 20 dogs the distal one-third of the small intestine and the proximal 10 cm of the ascending colon were resected. Bowel continuity was established by the telescoping technique to create an intestinal valve in ten dogs (group A) and by conventional end-to-end anastomosis in ten dogs (group B). Diarrhea and weight loss were similar in both groups. The ileal bacterial growth was significantly higher than the jejunum in group A (P less than 0.001) but not in group B. The jejunal bacterial growth in group B was significantly higher than that in group A (P less than 0.01). Intestinal transit times were 212 +/- 16.0, 219 +/- 152.4, and 163 +/- 85.8 minutes for normal dogs, groups A and B respectively. The competence of the normal ileocecal valve, the telescoped valve, and conventional anastomosis were 56 +/- 1.7, 49.9 +/- 17.4 and 13.2 +/- 7.8 cm of barium, respectively. Artificial intestinal valve formed by the telescoping technique is safe, simple, and effective in reducing bacterial overgrowth in the jejunum and appears to prolong intestinal transit time.

The healing and tensile strength of the gastroplasty staple line. An experimental study

Inverted and everted staple lines, with and without division of the anterior gastric wall, were performed in 15 mongrel dogs to simulate reduction gastroplasty staple line. There were no significant differences in tensile strength and healing between staple lines at different postoperative periods. The tensile strength of the inverted staple line seemed to be stronger due to breakage of the adjacent gastric tissue. However, the tensile strength of the everted stapling without division of the gastric wall, which is used clinically, was almost equal to that of normal gastric tissue. In addition, there was satisfactory healing 4 weeks postoperatively in the everted stapling without dividing the gastric wall. These results suggest that the everted staple line without division of stomach is not inherently weaker to any significant extent than if the gastric wall was divided or inverted. The reported failure rate of this procedure may be due to other factors.

Intestinal valve formation with a simple invagination technique

In 17 fully conditioned mongrel dogs, the small intestine approximately 50 cm proximal to the ileocecal valve was divided. Three centimeters of the proximal bowel was then inserted into the distal bowel and anastomosis was performed using interrupted 3-0 Dexon sutures in the seromuscular layer of the proximal end and through the entire thickness of the distal end. Two to four dogs were then sacrificed 2, 4, 6, 8, and 10 weeks postoperatively. Two dogs died 3 and 4 weeks postoperatively due to mechanical obstruction just proximal to the anastomosis by hair bezoar, and 15 survived without complications. Retrograde contrast radiologic examination of all segments showed no reflux. Microscopically, the serosal surface of the invaginated segment was found to be gradually covered with mucosa, and the whole segment formed a valvelike structure within 10 weeks time.

Electron microscopy of bacteriophage phi 6 nucleocapsid: three-dimensional image analysis

Electron micrographs of bacteriophage phi 6 nucleocapsids, negatively stained by neutralized phosphotungstate and tilted in a goniometer specimen cartridge, proved that the three distinct morphologies seen in the electron microscope are merely three different aspects of a single nucleocapsid structure and strongly suggested that this structure is dodecahedral.

Complement activation by heat-killed human kidney cells: formation, activity, and stabilization of cell-bound C3 convertases

Heat-killed kidney cells (HKKC) incubated with serum or purified C3 and factors B and D stain intensely for C3 by immunofluorescence. Binding of complement (C) did not occur if ethylenediaminetetraacetic acid (EDTA) was added to the C source or if factor B or D was omitted from the mixture of alternative pathway components. When the C-treated cells were washed, then incubated in purified C3 containing 10 mM EDTA, C3 conversion ensued, confirming the presence of a cell-bound C3 convertase. C3-reactive cells were not generated if EDTA was present during formation of the convertase. The addition of C3 nephritic factor (C3NeF) during formation of the C3 convertase from alternative pathway components greatly enhanced subsequent C3 cleavage, presumably by stabilizing labile C3bBb sites; however, binding of C3NeF did not appear to extend the half-life of the convertase, which was 35 min at 37 degrees C in each case. In contrast, little or no effect on C3 conversion could be detected after the addition of equivalent C3NeF to serum and HKKC. Thus, C activation by HKKC involves formation and activity of a cell-bound C3 convertase, which under certain circumstances can be stabilized by C3NeF.