Polarization states of diffracted light. Changes accompanying fiber activation

Measurement of the state of optical polarization of light diffracted from single, skinned and intact fibers of anterior tibialis muscle from Rana pipiens revealed a dependence upon rigor, activation, and sarcomere length (SL) change. Changes in total birefringence, delta nT, and differential field ratio value, rT, were determined. In a relaxed, skinned fiber the total birefringence value, delta nT, decreases as sarcomere length is increased from 2.1 microns to approximately 2.8-3.0 microns. From there it increases significantly to a value of approximately 1.8 x 10(-3) at a sarcomere length of 3.6 microns. The differential field ratio, rT, also shows a biphasic response to increasing sarcomere length, first exhibiting a rapid decrease over shorter SL and leveling out after the SL is beyond 3.0 microns. In comparison, relaxed intact fibers change substantially less upon sarcomere length change, showing little change in birefringence and a small bi-phasic change in rT. Skinned fibers were activated using a solution that has the same ionic strength as the relaxing solution and allows repeatable, and sustained activation. A decrease in both delta nT and rT was observed upon fiber activation. The decrease in delta nT and rT was slightly larger at shorter sarcomere lengths than at longer lengths. Relaxed fibers placed in rigor showed changes in delta nT and rT similar to those observed in activated fibers. These results are consistent with the hypothesis that, after activation, a significant portion of the thick filament cross-bridges rotate towards the actin filament resulting in redistribution of the interfilament mass content. They are also consistent with an average orientation of crossbridges in the overlap region different from that in the nonoverlap region.

[The role of medial medulla in the depressive responses in pulmonary and carotid arteries to injection of acetylcholine at fourth ventricle]

The role of medial medulla in the depressive responses in pulmonary and carotid arteries to injection of acetylcholine (ACh) at the fourth ventricle was studied by means of electrolytic destruction and microinjection of drugs at the relevant brain areas. It was found that (1) electrolytic destruction of medial medulla significantly diminished the depressive responses to ACh in pulmonary and carotid arteries; (2) destruction of nucleus tractus solitarius (NTS) at the level of the medullary obex did not affect the depressive responses in both arteries; obex did not affect the depressive responses in both arteries; (3) microinjection of 5-hydroxytryptamine (5-HT) blockers, cyproheptadine and 2-bromolysergic acid diethylamide (BOL), into the fourth ventricle or medial medulla could lessen the depressive responses to ACh in pulmonary and carotid arteries; (4) microinjection of naloxone in the same way could partially abolish the depressive responses. It is thus assumed that the ACh-induced depressive responses in pulmonary and carotid arteries are associated with the structural integrity of the medial medulla but not related to the central projection area of the buffer nerves. Therefore, the depressive responses in pulmonary and carotid arteries initiated by injection of ACh at the fourth ventrical are mediated by activating the 5-HT and endorphin systems of the medial medulla which in turn inhibits the tonic activities of the sympathetic preganglionic neurons in the spinal cord.

Lymphocyte subpopulation with low membrane potential in the blood of cyclosporin- and prednisone-treated patients: in vivo selectivity for T4 subset

Previous work on the mode of action of CsA revealed that this drug shifts the membrane potential of human periferal blood lymphocytes in vitro. Recently we have analyzed lymphocytes of cyclosporin-treated transplant patients. Membrane potential analysis with the DIOC6(3) fluorescence dye indicates that all the studied patients have a subpopulation of lymphocytes with low membrane potential and that this population is made up predominently of OKT4+ cells. However there is no correlation between the clinical events and the percentage distribution of lymphocyte subpopulations as defined by the membrane potential and the T4/T8 ratio of the total lymphocyte population.

Effects of calcium channel blockers on in vivo cellular immunity in mice

In vitro studies have shown that calcium channel blockers (CCB) inhibit lectin-induced lymphocyte proliferation. However, no in vivo effects have been documented yet. In this study we evaluated the effects of CCB on in vivo cellular immunity by using contact sensitivity to oxazolone in mice. From 15 to 30 twelve-week-old female C3H mice were randomized into: 0.9 NS (sham), ethanol, CsA, dexamethasone (DXM), verapamil, diltiazem, and nifedipine groups. These study agents were given daily from day 1 to day 9 subcutaneously to the shaved abdominal wall. The mice were sensitized with oxazolone to the abdominal wall on day 2 and challenged with oxazolone on the right ear on day 8. Delayed-type hypersensitivity was measured on day 10 and defined as the difference in thickness between the right (challenged) and left (control) ear of each mouse. The mean DTH of each study group was compared with that of the sham, and the statistical significance was determined by a Student's t test. The percentage of change in DTH from the sham was also calculated as: (mean DTH of study drug group-mean DTH of sham group)/mean DTH of sham group x 100%. A negative value meant a suppressive effect on DTH; a positive value, an enhancing one. The CsA, DXM, and nifedipine all had significant suppressive effects on DTH. Verapamil had a significant enhancing effect. Ethanol and diltiazem had no significant effect. More studies employing other antigens with several other cell-mediated response measurements along with DTH quantification should be done in order to determine the specificity of the immunosuppressive effect of CCB as well as the potential of any calcium antagonist as an adjuvant suppressive agent.

Incidence and morbidity of cytomegalovirus disease associated with a seronegative recipient receiving seropositive donor-specific transfusion and living-related donor transplantation. A multicenter evaluation

This retrospective study was conducted to identify the frequency of cytomegalovirus (CMV) disease in seronegative recipients of donor-specific transfusion (DST) and living-related donor (LRD) kidneys from seropositive donors. A total of 151 LRD transplants (TX) were performed at six transplant centers over a 3-year period. A total of 33 patients were identified as having been seronegative (pre-TX) for CMV, yet they had DST and a TX from a seropositive LRD. Of these patients, 12 (36.4%) seroconverted within the first 6 months post-TX and developed clinical CMV disease. Additional patients seroconverted, but did not have evidence of clinical disease and were not tested further. All TX centers, with the exception of one, had seronegative patients that became ill after receiving a seropositive DST/LRD TX. Six patients manifested their disease as a febrile illness with leukopenia and liver enzyme elevations, four had pneumonitis, and two developed CMV ulcerations of the colon (one of whom died from resultant sepsis). Of the 36 seronegative patients who received seronegative DST/LRD TX none became ill with CMV disease. Of the 72 seropositive patients who received DST/LRD TX, only 2 (2.8%) developed CMV illness (one, seropositive into seropositive, the other, seronegative into seropositive). Of the 33 seronegative patients receiving seropositive DST/LRD TX, 17 received antilymphocyte preparations (ALP), and 8 of these became ill (47.1%). Of 16 patients not receiving ALP, 5 (31.3%) developed clinical CMV illness. Of the 33 patients who were identified as having been seronegative for CMV yet received seropositive DST/LRD TX, the 12 who did develop CMV illness had two graft losses, one death, and a serum creatinine for the remaining 9 patients of 2.3 +/- 1.6 at last follow-up. The remaining 21 patients who developed no illness had a serum creatinine of 1.3 +/- 0.6 with no graft losses at the last follow-up. This evidence suggests that a prospective TX recipient who is seronegative for CMV who receives DST/LRD TX from a seropositive family member has a significant risk for developing morbidity related to clinical CMV illness.

Failure to thrive associated with chronic ulcer disease in a 9-year-old boy

Chronic peptic ulcer disease is not generally considered to cause failure to thrive. We are reporting a 9-year-old child who suffered from chronic recurrent abdominal pain and failure to thrive. Investigation revealed that the child also had bacterial overgrowth and evidence of malabsorption. These findings were considered to be due to chronic peptic ulcer disease which caused intermittent small bowel obstruction and gastric outlet obstruction. Successful treatment of the ulcer alone resulted in catch-up growth and an end to the chronic recurrent pain. Recurrent abdominal pain when associated with atypical features or failure to thrive should be adequately investigated. Although rare, chronic peptic ulcer disease with its sequelae should be considered in the differential diagnosis of failure to thrive.

Treatment of primary undifferentiated sarcoma of the liver with surgery and chemotherapy

Primary undifferentiated sarcoma of the liver is a rare tumor with survival reliant on total excision of the tumor. The authors report such a tumor, initially nonresectable, in a 7-year-old girl whose tumor was successfully excised following treatment with cisplatin and Adriamycin (doxorubicin). The light and electron microscopic details of this patient's tumor are presented.

Translation of type IV procollagen messenger RNA from cultured cat retinal pigment epithelial cells

The activity of type IV procollagen mRNA was detected in the total cytoplasmic RNA prepared from normal feline retinal pigment epithelial cells in culture. The translation products contained two distinct bands in the pro alpha chain region on SDS-PAGE, which were sensitive to collagenase digestion. Corresponding bands were identified in the immunoprecipitate of the translation products after reaction with an anti-type IV collagen antiserum and separation by protein A-Sepharose column chromatography.

Nonenzymatic glycosylation of bovine retinal microvessel basement membranes in vitro. Kinetic analysis and inhibition by aspirin

Incubation of intact bovine retinal microvessels or isolated retinal microvessel basement membranes (RVBM) with radioactive D-glucose or L-glucose, followed by basement membrane collagenous protein purification, resulted in the isolation of nonenzymatically glycosylated RVBM collagens. Type IV collagen was identified in the RVBM by selective salt fractionation, SDS-polyacrylamide gel electrophoresis, amino acid analysis, and immunoprecipitation with specific antibody. Kinetic analysis of the condensation of glucose with RVBM was carried out by labeling retinal microvessel basement membranes with D-[2-3 H]-glucose and D-[6-14 C]-glucose. The rate constant for aldimine product formation, k1, was 1.95 +/- 0.24 (SD) X 10(-4) mM-1 h-1, and the rate constant for the reversed reaction, k-1, was 5.9 +/- 1.0 X 10(-2) h-1. Based on a rate constant for the Amadori rearrangement, k2, of 8.8 +/- 1.0 X 10(-3) h-1, which was the rate-determining step, the half life of this reaction was 80 +/- 9 h. These data may be useful in estimating the glycosylation of retinal microvessel basement membranes in vivo. The nonenzymatic glycosylation of retinal microvessel basement membrane proteins was progressively inhibited by increasing concentrations (0.1 to 2.0 mM) of aspirin.

Stimulation of retinal capillary pericyte protein and collagen synthesis in culture by high-glucose concentration

The influence of glucose concentration on cell multiplication and protein synthesis was studied in synchronized, long-term cultures of bovine retinal microvessel pericytes. The cell multiplication rate and the mitotic rate were reduced in media containing 20 mM glucose to 57% and 54%, respectively, of that obtained in media containing 5 mM glucose. Elevated glucose, however, did not change the DNA content of individual cells. Protein and collagen synthesis were measured by the incorporation of radioactive proline and lysine, or the posttranslational production of hydroxyproline and hydroxylysine, respectively. High glucose stimulated protein and collagen synthesis per cell 2.2 +/- 0.10 (SD) and 2.1 +/- 0.06 times, respectively. Aspirin (0.5 mM), an inhibitor of nonenzymatic glycosylation, did not alter the effect of elevated glucose concentration on protein and collagen synthesis.

Mucosal proctectomy using an ultrasonic scalpel

Mucosal proctectomy is becoming the operation of choice in the surgical treatment of patients with ulcerative colitis and familial polyposis coli. Dissection of the rectal mucosa and submucosa from the underlying muscularis is often difficult and, in some instances, impossible to perform. The feasibility of using an ultrasonic device to perform mucosal protectomy was studied in eight dogs. This technique produced coagulative necrosis of the mucosa and muscularis mucosa with marked edema and congestion of the submucosa. The muscularis propria remained intact. Complete destruction of the distal 7 cm of rectal mucosa required a total duration of exposure to the ultrasonic probe of at least 12 minutes. In another five dogs, total colectomy was performed above the area of the mucosal proctectomy followed by endorectal pull-through of the ileum. Follow-up studies revealed healing of the ileonal anastomosis without retraction or stricture. This technique should allow mucosal proctectomy to be performed in those patients in whom standard dissection is not possible due to fibrosis of the submucosal plane.

The human fetal heart in the second trimester of gestation: a gross morphometric study of normal fetuses

One hundred fifty-three midtrimester fetuses obtained from normal pregnancies terminated for nonmedical reasons were studied to establish normal standard measurements. Mean, standard deviation, range, and percentiles of body weight, foot length, crown-rump length, biparietal diameter, cardiac weight, thickness of ventricles, and ventricular septum were derived by computer analysis. Statistical analysis showed no sex difference. Equations for predicting body weight, cardiac weight, and septal thickness were derived with the use of fetal age and biparietal diameter as variables. The mean ratio of septal to left ventricular wall thickness was 1.14 +/- 0.34; a ratio of 1.3 or greater was found in 25% and a ratio of 1.5 or greater in 10% of this cohort. The results are at variance with the reported high incidence of septal hypertrophy seen in normal developing fetal hearts. We suggest that septal hypertrophy, ratio of 1.5 or greater, may reflect disturbances in fetal or placental circulation and warrants careful monitoring of the pregnancy.

Phenotypic characterization of hepatic proliferation. Antigenic expression by proliferating epithelial cells in fetal liver, massive hepatic necrosis, and nodular transformation of the liver

Different forms of hepatocellular proliferation are seen in fetal livers, massive hepatic necrosis, and nodular transformation (nodular regenerative hyperplasia) of the liver. In an attempt to characterize the proliferating cells in these conditions, we studied the expression of several antigens by immunohistochemical methods. Alpha-fetoprotein (AFP), alpha 1-antitrypsin (AAT), a hepatocellular export protein, carcinoembryonic antigen (CEA), a marker of bile duct epithelial cells, and hepatitis B virus antigens (HBsAg, HBcAg), were localized by the peroxidase-antiperoxidase method in 11 fetal livers, 10 cases of nodular transformation, and 7 cases of massive hepatic necrosis. AFP was the most prevalent antigen in fetal hepatocytes. Many hyperplastic hepatocytes in nodular transformation contained AAT, but not oncofetal antigens, supporting the differentiated hepatocellular nature of these cells. A similar staining pattern was seen in two-cell-thick plates of hepatocytes in massive hepatic necrosis. In contrast, the ductlike structures at the periphery of necrotic lobules contained both AAT and CEA, suggesting that these cells exhibit features of hepatocytes and bile duct epithelial cells. Therefore, the appropriate term for these regenerating cells appears to be "ductular" or "biliary hepatocytes".

Histochemical study of Hurler's disease by the use of peroxidase-labelled lectins

Peroxidase-labelled lectins specific for various carbohydrate residues were used as histochemical reagents in the investigation of Hurler's syndrome. Peanut lectin was used to detect terminal D-galactose, wheatgerm lectin for N-acetyl-D-glucosamine, soybean lectin for N-acetyl-D-galactosamine, Tetragonolobus lotus lectin for alpha-L-fucose and Bandeiraea S. lectin for alpha-D-galactose. It was found that Kupffer cells in the liver and splenic reticulo-endothelial cells contain acid mucopolysaccharides which bind lectins in paraffin sections after appropriate fixation. The pattern of lectin binding suggests that such cells contain significant amounts of D-galactose, L-fucose, N-acetyl-D-galactosamine and N-acetyl-D-glucosamine. It is likely that the last named carbohydrate is present as a polymer. Neurones contain a different carbohydrate, rich in galactose and fucose but poor in N-acetyl-D-glucosamine. This compound is resident to lipid extraction. Hepatocytes, as a rule, do not react with lectins, most likely because of loss of the more soluble mucopolysaccharides during fixation. The results are consistent with the biochemical data of Hurler's syndrome and indicate that lectins can be a useful tool for the investigation of the cytochemistry of storage disorders.

Base substitutions, length differences and DNA strand asymmetries in the human G gamma and A gamma fetal globin gene region

We have studied differences arising subsequent to the 5 kilobase pair (kb) duplication that led to the human G gamma and A gamma fetal globin genes. The local occurrence of base substitutions in the duplicated 5 kb region correlates positively with the local AT base pair content. This correlation also occurs in two mouse beta-globin genes and in two mouse immunoglobulin genes. The relationship is valid for transcribed or nontranscribed DNA and for DNA that contains only coding sequences. Length differences in the fetal globin duplicated regions correlate positively with the occurrence of short direct repeats of greater than or equal 5 base pairs. Path analysis of the interrelationships of base composition, base substitutions, repeats and length differences provides an integrated view of the relative effects on chromosomal changes of these variables and of selection. The distributions along the chromosome of simple sequences and of base compositions show highly significant local asymmetries between the transcribed and nontranscribed strands of the DNA, which permit us to divide the fetal globin gene region into chromosomal domains. Comparable domains are present in DNA from other sources, including the mammalian viruses SV40 and polyoma virus strain A-2 in which some of the domains appear related to discrete functions.

Mapping and characterization of the hisD-unlinked nif mutants in Klebsiella pneumoniae

Two hisD-unlinked genes NifC5 and NifC7 are mapped in the chromosome of K. pneumoniae. The sequence of NifC5 and NifC7 is suggested as NifC5--gltB--NifC7--argG. The P1 infected E. coli lysate can transduce the mutant C-7 to be Nif+ transductant, yet fails to transduce the hisD-linked nif mutants to be Nif+ ones. This indicates that the gene encoding C-7 is not the structural gene of nitrogen fixation and is present in E. coli. It is actually a gene specifying the glutamate synthetase. SDS electrophoresis shows the marked low content of nitrogen reductase and immunoelectrophoretic test reveals the reduced amount of both nitrogenase and nitrogen reductase in the mutant cells.

Free vascularised bone graft using microvascular technique

The authors investigated 212 dried human fibulae to find out the length, the circumference and the entry points of nutrient artery to the fibula. Angiography of six freshly amputated limbs was studied to show the relationship of the posterior tibial artery and peroneal artery. Seven clinical cases of free vascularised fibula graft are reported. The length of the fibula graft varies from 10 cm to 20 cm. A postoperative 113M-In EDTMP examination revealed the blood supply to the grafted fibula was adequate. The bony healing and functional restoration of the extremities proved to be satisfactory.

Lymphomatoid granulomatosis in a child with acute lymphatic leukemia in remission

Lymphomatoid granulomatosis, a tumor-like process of unknown etiology, produced progressively destructive disease of the larynx, trachea and bronchi in an eight-year-old girl with acute lymphoblastic leukemia of five years duration. The leukemia had been in remission for 4 1/2 years at the clinical onset of the lymphomatoid granulomatosis. Whether this occurrence suggests that lymphomatoid granulomatosis is a type of neoplasm, or is associated with immunologic depression, cannot be stated. Fortunately rare, and of poor prognosis, the disorder may become more frequent with improved survival rate of patients with leukemia and other neoplasms.