Potential role for a guanine nucleotide regulatory protein in chemoattractant receptor mediated polyphosphoinositide metabolism, Ca++ mobilization and cellular responses by leukocytes

Islet activating protein from Bordetella pertussis toxin which ribosylates certain guanine nucleotide regulatory proteins causes a marked reduction of chemoattractant-elicited responses such as chemotaxis, O2 production and cAMP elevations in human polymorphonuclear leukocytes. The toxin appears to exert its effects by preventing the rapid breakdown of phosphatidylinositol 4,5-bisphosphate induced by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine, thereby inhibiting the increase in intracellular [Ca++] which normally follows chemoattractant stimulation. Responses of leukocytes exposed to Concanavalin A, the Ca++ ionophore A23187, or phorbol myristate acetate were not affected by the toxin. Thus the chemoattractant receptor appears to be coupled to a phosphoinositide specific phospholipase C through a guanine nucleotide regulatory protein. We propose that this complex of receptor-guanine nucleotide regulatory protein-phospholipase C may be applicable to the class of receptors which mobilize intracellular Ca++ by stimulating polyphosphoinositide breakdown.

Bronchial laceration in a newborn with persistent posterior pneumomediastinum

A large posterior pneumomediastinum that compromised the respiratory status and reaccumulated promptly after needle aspiration, aroused the suspicion of airway laceration. Tracheogram was consistent with laceration of the right bronchus. Evacuation of air with chest tube resulted in complete resolution of pneumomediastinum and healing of bronchial tear with no recurrence following removal of chest tube after seven days.

Characterization of a phosphatidylinositol 4-phosphate-specific phosphomonoesterase in rat liver nuclear envelopes

Incubation of rat liver nuclear envelopes with [gamma-32P]ATP resulted in the synthesis of phosphatidylinositol-[4-32P]phosphate (PIP). Degradation of endogenously labeled PIP was observed upon the dilution of the labeled ATP with an excess of unlabeled ATP. This degradation was most rapid in the presence of EDTA, and was inhibited by MgCl2 and CaCl2. To further characterize the degradative activity, phosphatidylinositol[4-32P]phosphate and phosphatidylinositol [4,5-32P]bisphosphate (PIP2) were synthesized and isolated from erythrocyte plasma membranes. The 32P-labeled phospholipids were then resuspended in 0.4% Tween 80, a detergent that did not inhibit degradation of endogenously labeled PIP, and mixed with nuclear envelopes. [32P]PIP and [32P]PIP2 were degraded at rates of 2.25 and 0.04 nmol min-1 mg nuclear envelope protein-1, respectively. Only 32P was released from phosphatidyl[2-3H]inositol-[4-32P]phosphate, indicating that hydrolysis of PIP was due to a phosphomonoesterase activity (EC 3.1.3.36) in nuclear envelopes. Similarly, anion-exchange chromatographic analysis of the water-soluble products released from [32P]PIP indicated that inorganic phosphate was the sole 32P-labeled product. Hydrolysis of PIP was most rapid at neutral pH, and was not affected by inhibitors of acid phosphatase or alkaline phosphatase. Hydrolysis of PIP was also not inhibited by nonspecific phosphatase substrates, such as glycerophosphate, p-nitrophenylphosphate, AMP, or glucose 6-phosphate. Hydrolysis was stimulated by putrescine, and was inhibited by inositol 2-phosphate, spermidine, spermine, and neomycin.

Solubilization and reconstitution of a nuclear envelope-associated ATPase. Synergistic activation by RNA and polyphosphoinositides

Treatment of isolated rat liver nuclear envelopes with 1% Triton X-100 solubilized 20-30% of the nuclear envelope protein and 85% of the ATPase activity. Chromatography on DEAE-Sepharose in 1% Triton X-100 at pH 7.5 removed all of the chemically measurable phospholipid from the bound ATPase activity; however, endogenously synthesized phosphatidylinositol [4-32P]phosphate (PIP) co-chromatographed with the ATPase activity on this column. Further purification by chromatography on heparin-agarose removed all of the [32P]PIP and RNA from the ATPase; however, the recovery of ATPase activity from this column was very low. RNA, polyadenylic acid, and polyguanylic acid stimulated the delipidated ATPase activity 4-6-fold. This activity was not further stimulated by the addition of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, or phosphatidic acid, but was stimulated 2-fold by the addition of phosphatidylinositol. Addition of 40 microM PIP and 50 micrograms of RNA/ml resulted in a 25-fold stimulation of basal ATPase activity. Phosphatidylinositol 4,5-bisphosphate, in the presence of RNA, was also able to stimulate ATPase activity but to a lower extent than that of PIP. Therefore, the nuclear envelope-associated ATPase appears to require interaction with a polynucleotide and PIP to express full activity. PIP, which is actively metabolized in the nuclear envelope, may therefore be involved in the regulation of the activity of this enzyme.

A technique for immediate manual external aortic counterpulsation during cardiac surgery

Intraaortic balloon pump counterpulsation is well established as a lifesaving measure. Aortic counterpulsation may be achieved externally as well as internally. A simple technique for manual external aortic counterpulsation during cardiovascular surgical procedures is presented. This technique is available on immediate demand and identical in effect to intraaortic balloon pumping, and it may be lifesaving in patients with acute cardiovascular decompensation since it allows time for institution of necessary emergency therapy.

Crystallization and preliminary x-ray investigation of a protein neurotoxin from the sea anemone Anthopleura xanthogrammica

Neurotoxic protein AX-I isolated from the sea anemone Anthopleura xanthogrammica has been crystallized. Two crystal forms were obtained. One form is tetragonal, space group P41 or P43 , with cell dimensions a = b = 40.74(2) A and c = 34.13(3) A. The second crystal form is hexagonal, space group P622 , with cell dimensions a = b = 72.23(2) A and c = 39.16(2)A. Density measurements indicate that the tetragonal crystals contain one toxin molecule/asymmetric unit. Both crystal forms diffract to high resolution.

Herpes simplex virus transmission: condom studies

The incidence of genital herpes simplex infections has risen at a rapid rate over the past 20 years. Sexually active young adults ask whether condoms will effectively block the transmission of herpes simplex virus from one individual to another. Using a laboratory plunger model to stimulate human coitus, the authors have shown that high concentrations of HSV-2 did not cross the latex or natural membrane condoms that were tested. We have also shown that high concentrations of HSV-2 left in contact with a condom for 8 hr does not penetrate the barrier. This study gives good indirect evidence that condoms block the transmission of herpes simplex virus.

The clinical utility of the lupus band test

In order to determine the clinical utility of the lupus band test, the presence of dermal-epidermal junction (DEJ) deposits of IgG, IgM, IgA, C3, C4, Clq, and properdin were studied in biopsies of clinically normal deltoid area skin from 102 patients with systemic lupus erythematosus (SLE) and 151 patients with other rheumatic diseases. One or more proteins were detected at the DEJ in 72.6% (74 of 102) of patients with SLE and in 36.4% (55 of 151) of the other patients, yielding a specificity of 64% and a predictive value of 57%. The predictive value for the diagnosis of SLE was greatest with C4 (100%), properdin (91.3%), and IgA (86.2%) and lowest with IgM (59%). Specificity and predictive value increased with the number of proteins detected at the DEJ. The results suggest that more rigid criteria are required before diagnostic significance is attached to a positive result on the lupus band test.

A long-term longitudinal study of anticentromere antibodies

A longitudinal retrospective study of 37 patients previously tested for anticentromere antibodies (ACA) in 1982 was carried out. No ACA were found in stored sera from 22 ACA-negative patients including 1 patient with CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia). All ACA-positive patients, with 1 exception, were found to have ACA in their sera over prolonged periods of time. One patient developed ACA for the first time when the third feature of the CREST syndrome (Raynaud's phenomenon) was noted. Anticentromere antibodies were IgG, and no consistent change in titer over time was found.

Skeletal muscle differentiation in Wilms' tumor. Antibody identification and explant culture

We studied a case of Wilms' tumor with focal areas of well-differentiated skeletal muscle by immunoperoxidase staining using anti-skeletal muscle myosin and by tissue culture explant of the tumor. Strong immunostaining occurred in areas of well-differentiated muscle but also occurred in focal areas where the cells were undifferentiated. The primary explant of this tumor was attempted using standard serum-containing culture media and a serum-free hormonally defined culture medium. While serum-containing culture media gave rise to a fibroblastlike cell population, the serum-free hormonally defined medium produced cells of myoid origin. Ultrastructurally, all stages of early myogenesis from myoblasts to myotubules were observed in this primary explant grown in serum-free medium.

A clinical comparison of dentinal slot retention with metallic pin retention

Twenty-two pairs of extensive amalgam restorations were placed in 19 patients. One amalgam of each pair had self-threading pin retention, and the other had dentinal slot retention. Evaluations were done at baseline, at one, and two years. After two years, 17 pairs of amalgams were available for evaluations. The data obtained can be summarized as follows: 100% (17) of the slot-retained amalgams were clinically acceptable, whereas 94.1% (16) of the pin-retained amalgams were acceptable. It can be concluded that, in clinical usage, dentinal slot retention is as effective as self-threading pin retention in extensive amalgam restorations.

Phosphorylation of rat liver nuclear envelopes. I. Characterization of in vitro protein phosphorylation

Nuclear envelopes were prepared from purified rat liver nuclei by lysis with heparin, digestion with deoxyribonuclease I (DNase I), or sonication. The envelopes were fractionated by centrifugation on sucrose density gradients and analyzed for protein kinase activity using endogenous and exogenous protein substrates and [gamma-32 P]ATP. The protein kinase activity toward endogenous proteins was markedly affected by the method used to isolate the envelopes, with sonication producing a preparation with very low activity. At least 12 phosphoproteins in nuclear envelopes isolated by the heparin or DNase I method were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. A 32P-labeled material migrating with an apparent Mr = 3000 was extracted with chloroform:methanol:HCl and was identified as a mixture of phospholipids. Total 32P incorporation into nuclear envelopes peaked at 5 min of incubation, followed by a decrease in labeled products. This decrease was due to both phosphoprotein phosphatase activity and degradation of the lipid products. The highest protein kinase activity toward endogenous proteins was expressed with [gamma-32P]ATP in the presence of MgCl2; however, some phosphorylation also occurred with MnCl2, CoCl2, NiCl2, and [gamma-32P]GTP in the presence of MgCl2. Nuclear envelope protein phosphorylation was unaffected by cyclic nucleotides and calmodulin, slightly inhibited by CaCl2, MnCl2, CoCl2, disulfides, and sulfhydryl alkylating agents, and strongly inhibited by LaCl3 and phosphatidylglycerol. Nuclear porelamina complexes isolated from phosphorylated envelopes contained phosphoproteins of 7, 20, 51, 59, and 70 kDa. Incubation of pore-lamina complexes isolated from unlabeled envelopes with [gamma-32P]ATP resulted in 32P incorporation into the 20-, 51-, and 50-kDa proteins.

Phosphorylation of rat liver nuclear envelopes. II. Characterization of in vitro lipid phosphorylation

Incubation of nuclear envelopes isolated from normal rat liver with [gamma-32P]ATP resulted in the rapid labeling of chloroform-soluble products. These products were identified as phosphatidic acid (PA), phosphatidylinositol 4-phosphate (DPI), and phosphatidylinositol 4,5-bisphosphate (TPI) based on their chromatographic mobilities on Silica Gel H and cellulose thin layer plates, and by analysis of their deacylation products by high pressure liquid chromatography. The extent of phosphorylation of these products was dependent on the method used to isolate the nuclear envelopes. Relatively gentle isolation methods, such as lysis of purified nuclei with heparin or digestion with deoxyribonuclease I, produce nuclear envelopes which possess significantly higher lipid kinase activity than do envelopes isolated by sonication. Incorporation of 32P into PA, DPI, and TPI in 2 min under standard assay conditions was 13, 152, and 22 pmol/mg of membrane protein, respectively. Degradation of labeled DPI and TPI was evident after 2-5 min of incubation. Nuclear envelope-associated diacylglycerol kinase, phosphatidylinositol kinase, and DPI kinase are characterized with regard to their pH and Mg2+ requirements. The effects of metals, phospholipids, and sulfhydryl reagents on these kinase activities are also described.

Controlled trial of nifedipine in the treatment of Raynaud's phenomenon

17 patients with moderate to severe Raynaud's phenomenon were entered into a 6 week randomised double-blind crossover study to compare the efficacy of nifedipine with that of placebo. Nifedipine significantly reduced the frequency of attacks and also the severity of attacks, which was assessed by the patients on a linear analogue scale. Patients gave nifedipine a significantly higher drug-effectiveness score than placebo. Skin temperature recovery times were not affected by treatment with nifedipine. 12 of the patients regarded nifedipine as effective in reducing the frequency and severity of Raynaud's phenomenon.

The diagnostic laboratory tests for histoplasmosis: analysis of experience in a large urban outbreak

Of 495 patients reported in a large urban histoplasmosis outbreak, we studied 276 whose serologic tests were done in a single laboratory. Serologic test results were positive in 96% of these patients (compared with less than 5% of controls from an endemic area), cultures were positive in 22%, and special stains in 19%. The immunodiffusion test results were negative in 13% of patients who had positive findings by complement fixation, and 1% had positive results only by immunodiffusion. The complement fixation test was almost twice as sensitive as the immunodiffusion test in patients with subclinical infection. The serologic response differed significantly among the clinical syndromes with higher titers in cavitary and lower titers in disseminated disease. Factors associated with titers of 1:64 or greater to both antigens were black race and immunocompetence. High mycelial titers were also associated with more intense exposure, and high yeast titers were associated with age less than 36 years. No prognostic significance could be proved for fourfold titer rises or falls or persistence of precipitins.

An automated PSRO-utilization review system

A set of computer programs collects, processes, and reports Professional Standards Review Organization (PSRO) and utilization data for all patients at the Miami Heart Institute. They help reduce the time spent by physicians in PSRO and utilization review activities and ease the clerical work load required to comply with rules and guidelines. Daily printed reports provide attending physicians with their patient census and inform them of the next scheduled PSRO review dates for each of their patients. Reports are produced also for the Utilization Review Committee and the Institute's PSRO office. This set of programs is part of a comprehensive automated hospital information system and has been designed to respond rapidly to the frequent changes in regulations and policies dictated by the administering agency. The PSRO subsystem had been in uninterrupted operation for over 6 years and has mitigated escalating clerical and, therefore, health care costs. Physicians' acceptance of this subsystem had been adequate; however, developmental and maintenance costs are high in comparison with other applications within the hospital information system. This article describes the methodology used in complying with PSRO requirements. It does not attempt to evaluate the impact of PSRO on quality of care or length of hospital stay.

The role of the physician's assistant in a university-based pediatric surgical service

Physician's Assistants (P.A.), recent additions to the health profession, have proved valuable as "extenders" for primary physicians in relatively remote rural areas. More specialized surgical assistants have been trained for the community-practicing surgeon. The introduction of physician's assistants into university centers has been proceeding at a slower pace. A need has existed for an accurate assessment of the role of the P.A. in a residency-training program. In subspecialties, such as pediatric surgery and thoracic surgery, an increasing patient load has usually required a corresponding increase in junior resident staff. This resident coverage is usually dependent upon the availability of general surgical house staff since pediatric surgical trainees are currently fixed in number. Foreign medical graduates are no longer available in large numbers and general surgical programs themselves are being reevaluated and the number of trainees decreased. In this setting physician's assistants can be used to augment patient coverage by acting as junior surgical residents.

Fabrication of removable stone dies using cemented dowel pins

Proper dowel pin placement in the working cast is important in the fabrication of a cast restoration. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship.

Hemolytic-uremic syndrome: a diagnostic and therapeutic dilemma for the surgeon

The hemolytic-uremic syndrome consists of microangiopathic hemolytic anemia, acute renal failure, and thrombocytopenia following a prodromal illness of gastroenteritis or upper respiratory infection. The syndrome can present in dramatic fashion with severe abdominal pain and signs of peritonitis suggesting an acute surgical crisis. In a series of 25 patients, 40% had abdominal pain, 25% had abdominal tenderness, and 20% had peritoneal signs. Clues to diagnosis in the early stages of the acute illness were mild to moderate hypertension, abnormal peripheral blood smear, anemia despite dehydration, and proteinuria. Significant abdominal pain and x-ray evidence of colitis may occur before development of typical laboratory findings, and these were evident in at least one case. Three patients underwent laparotomy for suspected bowel perforation. Colitis without perforation was found in all cases. In the absence of documented perforation, toxic megacolon, or intussusception, the decision to perform laparotomy in patients with hemolytic-uremic syndrome who have signs of peritonitis must be individualized. Failure to recognize the underlying renal problem can lead to serious errors in fluid and electrolyte management and delay of appropriate therapy.

Immunogenicity of serogroup A and C Neisseria meningitidis polysaccharide vaccines administered together in humans

Serogroup A and C Neisseria meningitidis polysaccharide vaccines were administered to U.S. Army recruit volunteers, either two weeks apart or at the same time into two different sites on the same arm, to determine what effect, if any, the combined administration would have on the immunogenicity of each individual component. The vaccines were found to be as immunogenic when administered together as when given separately; in fact, the data suggest a possible enhancement of the response, as measured by the radioactive antigen binding test, to both components when the two vaccines are given together.

Effect of immunosuppressants on dogs exposed two and one-half years previously to Blastomyces dermatitidis

Observation of 33 dogs exposed to Blastomyces dermatitidis over a 2 1/2 year period is reported. During the first 1 1/2 years six dogs died and 23 (77%) developed skin lesions. Clinical evidence of disease in all the animals then subsided and remained so through another year of observation. Nine animals were sacrificed after 120 weeks and several tissues were cultured from each one. The remaining 18 were given immunosuppressants--azathioprine, prednisone, and cyclophosphamide--for eight weeks prior to autopsy. About one-half of the dogs were found to be infected with Histoplasma capsulatum and all were negative for B. dermatitidis by culture. The dogs were thought to have been inadvertently exposed to H. capsulatum during the first eight weeks of observation from a nearby soil plot before being moved to a more remote shelter. Skin testing with histoplasmin and blastomycin and complement-fixation (CF) tests, performed at various intervals after exposure to B. dermatitidis, appeared to reflect the course of disease with the number of reactors to the H. capsulatum antigens remaining relatively high while the number of reactors to B. dermatitidis antigens fell with the passage of time. The blastomycin skin test results in these dogs, however, persisted far longer than positive Blastomyces CF results. These data suggest that most dogs exposed to B. dermatitidis exhibit clinical symptoms of disease after about 12 weeks, persisting for about one year. The majority of animals recover spontaneously and completely. With H. capsulatum, however, the infection can be subclinical for at least a two-year period.

Comparison of immunodiffusion and complement fixation tests in the diagnosis of histoplasmosis

The immunodiffusion and complement fixation tests for histoplasmosis were compared on 2,090 initial sera from 70 proven cases of histoplasmosis, 177 routine chest hospital patients, and 1,843 coal miners from outside the major endemic area for histoplasmosis. The complement fixation test using histoplasmin as antigen detected antibodies in the sera of 72.8% of the 70 proven cases, while the complement fixation test using yeast antigen detected antibodies in 94.3% of the case sera, and the immunodiffusion test using histoplasmin antigen detected antibodies in 90% of the sera. The tests were also compared for sensitivity, specificity, and ease of performance.

Distribution of Blastomyces dermatitidis in dogs with skin test and serologic results following airborne infection

Reported is a short term (16 week) experiment to determine the distribution of B. dermatitidis in dogs when infected by the natural inhalation route by receiving about 250,000 viable particles during a 24h. exposure. Four dogs were positive to blastomycin and 1 to histoplasmin prior to exposure. Post exposure, all dogs developed positive skin tests to blastomycin by the 4th week with considerable cross reaction to histoplasmin. Serologic tests showed more poritive CF tests to Histoplasma than to Blastomyces so that the test appears of no practical value. Although 22 tissues were cultured on each dog, only 1 or 7 dogs was positive for B. dermatitidis by 2 weeks. At 4 weeks, 57% of the dogs were positive by culture and at 12, 15, and 16 weeks, all were positive. One dog developed eye lesions and became emaciated.

Campylobacter fetus infection in humans. Analysis of three cases

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Improved culture method for the isolation of Histoplasma capsulatum and Blastomyces dermatitidis form contaminated specimens

Studies were performed to evaluate a method for selective isolation of Histoplasma capsulatum and Blastomyces dermatitidis from contaminated specimens. Ammonium hydroxide placed on an agar medium surface was found to inhibit the growth of many bacteria, yeasts, and saphrophytic fungi normally found in specimens such as animal tissues and sputum. In one study involving the culture of B. dermatitidis from canine tissues, 24% more isolations were obtained on a medium using NH4OH compared with a similar medium. Increases in the isolation of H. capusulatum from sputum specimens were also obtained, ranging from 20 to 32% compared with four other media without NH4OH.

Antibody responses to meningococcal polysaccharide vaccines

Over the past 4 years 19 lots of group C polysaccharide vaccine and five lots of group A polysaccharide vaccine have been tested for their immunogenicity in man. For each lot tested, groups of 18 to 50 men received 50 mug of vaccine subcutaneously. Sera were obtained prior to and 2 weeks after vaccination. The analytical and serological methods used in these studies were Sepharose 4B chromatography for the estimation of molecular size, the radioactive antigen binding assay, and the indirect hemagglutination (IHA) test for measuring the antibody response. Results have shown that the radioactive antigen binding assay is preferable to the IHA test as a measure of antibody response. Group C meningococcal vaccines have been highly stable when stored at 4 C in powdered form. All lots of group C vaccine tested to date have been of equal potency, with molecular weight varying from 520,000 to 2,000,000. Group A polysaccharides have been found to be unstable after 2 years of storage at 4 C. Optimal antibody response to the group A vaccines appears to be directly related to the molecular size of the preparation.