Protein stitchery: design of a protein for selective binding to a specific DNA sequence

We present a general strategy for designing proteins to recognize DNA sequences and illustrate this with an example based on the "Y-shaped scissors grip" model for leucine-zipper gene-regulatory proteins. The designed protein is formed from two copies, in tandem, of the basic (DNA binding) region of v-Jun. These copies are coupled through a tripeptide to yield a "dimer" expected to recognize the sequence TCATCGATGA (the v-Jun-v-Jun homodimer recognizes ATGACTCAT). We synthesized the protein and oligonucleotides containing the proposed binding sites and used gel-retardation assays and DNase I footprinting to establish that the dimer binds specifically to the DNA sequence TCATCGATGA but does not bind to the wild-type DNA sequences, nor to oligonucleotides in which the recognition half-site is modified by single-base changes. These results also provide strong support for the Y-shaped scissors grip model for binding of leucine-zipper proteins.

DNA flow cytometry in pheochromocytoma and paraganglioma

Flow cytometric DNA analysis was performed on 19 adrenal pheochromocytomas and 6 extra-adrenal paragangliomas in parallel with clinical and histopathological review to determine the usefulness of this technique to predict biologic behavior of these tumors. In pheochromocytomas and paragangliomas, tetraploidy or near-tetraploidy occurred in 32% and 33% and aneuploidy in 10% and none respectively. A case of malignant pheochromocytoma had diploid DNA content. Occurrence of aneuploidy or tetraploidy is frequent in clinically benign tumors in conjunction with a marked degree of nuclear atypia and cannot be a predictor of malignancy.

Involvement of SecB, a chaperone, in the export of ribose-binding protein

Ribose-binding protein (RBP) is an exported protein of Escherichia coli that functions in the periplasm. The export of RBP involves the secretion machinery of the cell, consisting of a cytoplasmic protein, SecA, and the integral membrane translocation complex, including SecE and SecY. SecB protein, a chaperone known to mediate the export of some periplasmic and outer membrane proteins, was previously reported not to be involved in RBP translocation even though small amounts of in vitro complexes between SecB and RBP have been detected. In our investigation, it was shown that a dependence on SecB could be demonstrated under conditions in which export was compromised. Species of RBP which carry two mutations, one in the leader that blocks export and a second in the mature protein which partially suppresses the export defect, were shown to be affected by SecB for efficient translocation. Five different changes which suppress the effect of the signal sequence mutation -17LP are all located in the N domain of the tertiary structure of RBP. All species of RBP show similar interaction with SecB. Furthermore, a leaky mutation, -14AE, generated by site-specific mutagenesis causes reduced export in the absence of SecB. These results indicate that SecB can interact with RBP during secretion, although it is not absolutely required under normal circumstances.

Treatment of postcataract fibrinous membranes with tissue plasminogen activator

PURPOSE

The purpose of this study is to investigate the efficacy and toxicity of tissue plasminogen activator (tPA) in treatment of postcataract fibrinous membranes.

METHODS

The authors injected 25 micrograms of tPA into the anterior chamber of 52 pseudophakic eyes with moderate to severe fibrinous membranes that developed after cataract surgery.

RESULTS

Intraocular tPA injection resulted in complete fibrinolysis in 47 of 52 eyes (90%) and partial fibrinolysis in 5 of 52 eyes (10%). In cases of complete fibrinolysis, resolution of the fibrinous membrane occurred within 30 minutes in 22 of 47 eyes (47%) and within 1 hour in 25 of 47 eyes (53%). No evidence of toxicity was observed as measured by slit-lamp biomicroscopy, intraocular pressure, and corneal endothelial cell density, size, and morphology. Complications of tPA administration included periorbital pain (4 eyes), anterior chamber hemorrhage (4 eyes), and anterior chamber turbidity (3 eyes).

CONCLUSION

The authors believe that intraocular tPA is effective and safe in the treatment of postcataract fibrinous membranes.

Arterial supply of the anterior ear

Twenty cadaver auricles were injected with a latex solution to define the arterial supply of the anteroauricular surface. Two arterial networks exist, the network of the triangular fossa-scapha and the network of the concha. Both eventually communicate on the anthelix. The triangular fossa-scapha network originates from one subbranch of the upper auricular branch of the superficial temporal artery and from branches of the posterior auricular artery that come through the earlobe and triangular fossa and over the helical margin. The conchal network is provided by two to four perforators that come from the posterior auricular artery, piercing the conchal floor. Auricular branches of the superficial temporal artery in the preauricular region and their communications with the posterior auricular artery also were confirmed. We believe that a greater understanding of the detailed arterial anatomy in this area allows one to develop safely a variety of surgical techniques for reconstruction of the ear.

Pulmonary embolism as the initial manifestation of large cell lung cancer--a case report with review

Lung cancer is known as a risk factor of pulmonary embolism. We experienced a case of pulmonary embolism combined with pleural effusion and pleuritic chest pain as the initial manifestation of large cell lung cancer, which is a relatively rare cell type of lung cancer in Korea. We report it with a review of the literature.

Subacute necrotizing lymphadenitis--a collective clinicopathological and immunohistochemical study

Subacute necrotizing lymphadenitis (SNL) is a well documented and unique clinicopathologic entity, although its etiology and pathogenesis have not been clearly established. Microscopically, cortical and paracortical necrotizing lesions with karyorrhexis, abundant nuclear debris and infiltration of large mononuclear cells are characteristic. This study analyzed the common clinical and pathological features of 118 patients with SNL and the nature of the mononuclear cells. Patients were generally young women and revealed cervical lymphadenopathy with tenderness, fever, leukopenia and elevation of the erythrocyte sedimentation rate. Features of the adjacent uninvolved area in the lymph node included a starry sky pattern, follicle centers, sinus histiocytosis or aggregation of foamy histicoytes. There was an inverse relationship between the extent of necrosis and of histocytic infiltration but not between the extent of necrosis and the duration from the onset of symptoms to the diagnosis. Immunohistochemically the infiltrated mononuclear cells of the affected foci were T lymphocytes and histiocytes. The clinical, histological and immunohistochemical features suggest that SNL represents a hypersensitivity reaction to certain infectious agent without forming granuloma.

Comparison of superior oblique tendon expander to superior oblique tenotomy for the management of superior oblique overaction and Brown syndrome

We compared surgical results of superior oblique tenotomy to the superior oblique silicone expander for the treatment of superior oblique overaction and Brown syndrome. Of 24 patients with bilateral superior oblique overaction, 13 underwent tenotomy and 11 had the silicone expander procedure. Reduction of A-pattern to within 10 prism diopters was achieved in 12/13 (92.3%) tenotomy patients and in 10/11 (90.9%) patients undergoing silicone expander (P greater than .05). Correction of superior oblique overaction on versions to within +/- 1 dysfunction was achieved in 22/26 (84.6%) of the tenotomies, and 21/22 (95.5%) silicone expander procedures (P greater than .05). Zero superior oblique dysfunction was found after 14/26 (53.8%) tenotomy procedures versus 18/22 (81.8%) silicone expander operations (P = .041). Superior oblique paresis occurred postoperatively in 4/13 (30.8%) tenotomy patients, whereas none of the 11 patients in the silicone expander group had superior oblique paresis (P = .044). Six patients who underwent superior oblique tenotomy for superior oblique overaction had preoperative stereopsis; following surgery, only two maintained the same level of stereopsis, and three patients totally lost all stereo acuity. All patients in the silicone expander group either maintained or had improved stereo acuity postoperatively. Seven patients with true Brown syndrome were operated on: three underwent the silicone expander procedure and four had a superior oblique tenotomy with an ipsilateral inferior oblique recession. The combination of superior oblique tenotomy with simultaneous ipsilateral inferior oblique recession resulted in an undercorrection in two of the four patients, whereas all three patients in the silicone expander group showed excellent ocular motility postoperatively, with two having normal versions and one a -1 residual limitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Contaminant reduction by ventilation in a confined space model--toxic concentrations versus oxygen deficiency

Airborne contaminants can create hazardous conditions in confined spaces (CS) across a broad range of concentrations, e.g., from relatively low, potentially toxic levels (ppm) to much higher levels (%) causing oxygen deficiency. This study investigated ventilation characteristics for isobutylene (IBE) at relatively low concentrations, simulating toxic levels. Experimental data were compared to results from previous studies of oxygen deficiency. Data were obtained at several locations in a cubical CS model, with several variable test parameters: ventilation mode (exhaust and supply), volume flow rate ("air changes" per hour), and ventilation inlet/outlet elevation (% of model height). Findings indicated similar ventilation characteristics, in general, for simulated toxic (IBE) levels compared to oxygen deficiency. Both IBE and O2 deficiency data have shown that supply ventilation is typically more effective than exhaust and that CS locations aligned with supply outlets experience much more rapid contaminant reduction than do other locations. The data suggest that highly accurate predictions of ventilation characteristics cannot be expected for all cases with widely different contaminants and concentrations. Findings from this study indicate that ventilation guidelines for one range of contaminant concentration (e.g., causing oxygen deficiency) can be extended reasonably to encompass a broader range of concentration (e.g., to include toxic or flammable atmospheres).

Evaluation of 99mTc-hexamethylpropyleneamine oxime cerebral blood flow mapping after acute focal ischemia in rats

Although the blood flow tracer hexamethylpropyleneamine oxime is now widely used for cerebral blood flow mapping using single-photon emission computed tomography, its uptake into acutely ischemic brain has not been well studied. We performed a double-label autoradiographic study in which 99mTc-hexamethylpropyleneamine oxime uptake was compared with [14C]iodoantipyrine-derived cerebral blood flow 0.5, 24, and 72 hours after middle cerebral artery occlusion in 11 rats. We noted excellent correspondence between iodoantipyrine and hexamethylpropyleneamine oxime autoradiograms at all times with both simultaneous tracer injection and 30-minute separation of tracer injections. When the ischemic and hyperemic areas were measured from the same brain section using the two different tracers, hexamethylpropyleneamine oxime underestimated the iodoantipyrine-derived areas by less than 1% (95% confidence interval -2.9% to 2.3%). The maximum discrepancy (-19%) was seen at high flows. When the two tracers were injected separately, the uptake of hexamethylpropyleneamine oxime was not linear compared with iodoantipyrine-derived cerebral blood flow, but the relation became linear after the Lassen correction factor was applied. Hexamethylpropyleneamine oxime uptake thus accurately represents cerebral blood flow 0.5-72 hours after acute cerebral ischemia.

Gamma-interferon effects on human fibroblasts from Tenon's capsule

Gamma-interferon (G-IFN) exhibits antiproliferative effects, inhibits collagen synthesis by fibroblasts, and may help to regulate the turnover of fibrous tissue. Fibroblasts from Tenon's capsule are cellular components that contribute to unsuccessful glaucoma filtration surgery. Therefore, the authors studied the effects of G-IFN on growth, wound closure, collagen synthesis, and extracellular matrix in cultured human Tenon's capsule fibroblasts (HTCF). HTCF incubated with G-IFN at doses of 1 to 1000 U/ml showed cellular heterogeneity, with some cells showing morphologic changes characteristic of senescence, and a dose-dependent inhibition of wound closure. At 1000 U/ml, G-IFN reduced collagen synthesis by 57%, reduced immunofluorescent staining of collagen type I and fibronectin network, and altered the organization of actin microfilaments into large cable-like structures. Cell proliferation and viability were not affected at any concentration of G-IFN. These results suggest that G-IFN may be useful to modulate wound healing after filtration surgery.

A single-stage two-flap method of total ear reconstruction

A single-stage two-flap method of total ear reconstruction in congenital microtia is reported. This method was derived from the one-stage reconstruction described by Song and Song. Two flaps defined by vascular basis were elevated on the mastoid area: the superficial skin flap supplied mainly by subcutaneous pedicled arteriole perforators from the posterior auricular artery and the deeper axial-pattern fascial flap including the posterior auricular artery itself. The ear framework, exaggeratedly carved using autologous rib cartilage, could be inserted easily between the two flaps, simultaneously producing the auriculocephalic angle and the conchal wall. Intraoperative expansion of the skin flap and postoperative external ear molding also were performed to create aesthetically pleasing ears.

Functioning free latissimus dorsi muscle transplantation: anterogradely positioned usage in reconstruction of extensive forearm defect

We present a patient with successful functional recovery of a severely injured upper extremity after a microneurovascular free latissimus dorsi muscle and combined composite skin were transplanted with an anterograde position. In our patient, the anterogradely positioned usage of the lastissimus muscle offered two major advantages; one advantage was the direct anastomosis of a more proximal healthy uninjured recipient nerve without interpositional nerve graft, and the other, one-stage coverage including the elbow wound with combined scapular skin flap. From our result, we deduce that a neurovascular free latissimus dorsi muscle transplantation with an anterograde position is selectively indicated in functional recovery of an extensively injured forearm.

Normal splenic size in infants and children: sonographic measurements

The purpose of this study was to establish guidelines for normal splenic size at different ages by using a simple and reproducible sonographic method. Two hundred thirty patients, from neonate to 20-year-old, had sonography because of abdominal and/or pelvic problems unrelated to the spleen. Findings on sonograms of the liver and kidneys were normal in all cases. Splenic size was measured by obtaining a coronal view that included the hilum, while the patient was breathing quietly. The greatest longitudinal distance between the dome of the spleen and the tip (splenic length) was measured and correlated with age, height, and weight. The following guidelines are proposed for the upper limit of normal splenic length based on this simple, easy to use, one-measurement technique: splenic length no greater than 6.0 cm at 3 months, 6.5 cm at 6 months, and 7.0 cm at 12 months, 8.0 cm at 2 years, 9.0 at 4 years, 9.5 cm at 6 years, 10.0 cm at 8 years, 11.0 cm at 10 years, 11.5 cm at 12 years, 12.0 cm at 15 years or older for girls, and 13.0 cm at 15 years or older for boys. Twenty-two patients with known abnormalities of the spleen were randomly selected and their splenic lengths compared with the proposed guidelines; in each case, the length of the spleen exceeded the upper limit of normal for that age. Normal values of a single measurement of the greatest longitudinal diameter of the spleen, from the dome to the tip measured at the hilum in the coronal plane, were obtained in patients from newborn to 20 years old.

Mutations that affect the folding of ribose-binding protein selected as suppressors of a defect in export in Escherichia coli

It has been proposed (Randall, L. L., and Hardy, S. J. S. (1986) Cell 46, 921-928) that export of protein involves a kinetic partitioning between the pathway that leads to productive export and the pathway that leads to the folding of polypeptides into a stable conformation that is incompatible with export. As predicted from this model, a decrease in the rate of export of maltose-binding protein to the periplasmic space in Escherichia coli resulting from a defect in the leader sequence was able to be partially overcome by a mutation that slowed the folding of the precursor, thereby increasing the time in which the polypeptide was competent for export. (Liu, G., Topping, T. B., Cover, W. H., and Randall, L. L. (1988) J. Biol. Chem. 263, 14790-14793). Here we describe mutations of the gene encoding ribose-binding protein that were selected as suppressors of a defect in export of that protein and that alter the folding pathway. We propose that selection of such suppressors may provide a general method to obtain mutations that affect the folding properties of any protein that can be expressed and exported in E. coli.

Effect of a modified rectus tuck on anterior ciliary artery perfusion

Strabismus surgery results in the permanent interruption of anterior ciliary blood flow, predisposing the eye to anterior segment ischemia (ASI). A primate model was used to assess the effectiveness of a new muscle-scleral tuck for preserving anterior ciliary artery circulation. The model consisted of removing 3 rectus muscles from both eyes of 2 rhesus monkeys, then performing a tuck on the inferior rectus (IR) right eye while leaving the left IR as a control. Four weeks later, a modified tuck was performed on the virgin left IR. Fluorescein iris angiograms of both eyes were obtained, and preoperative angiograms at 5-15 sec. showed normal 360 degrees perfusion. Postoperative follow-up angiograms showed segmental superior temporal filling defects and preservation of perfusion in the distribution of the IR. Comparison of fellow eyes tucked vs control IR showed no difference in the filling pattern in both monkeys. Comparison of the same eye before and after tuck also showed essentially the same filling pattern in all 4 eyes with preservation of inferior circulation. Our conclusion is that the modified tuck preserves the anterior ciliary blood flow and may be useful as a muscle-strengthening procedure in patients predisposed to developing ASI.

High-dynamic-range heterodyne measurement of optical spectra

The dynamic range of a conventional heterodyne spectroscope is limited by the intensity noise and the shot noise of the optical spectrum under test. We propose to improve the dynamic range by several orders of magnitude by using phase-sensitive detection. We demonstrate the feasibility of our method by measuring the tails of a distributedfeedback laser line 60 dB below maximum, which gave an improvement of 35 dB compared with that of the conventional technique: 15 dB by using a balanced receiver and another 20 dB by the phase-sensitive detection.

Effects of iodinated fatty acid ester on human hepatocellular carcinoma cells

The interaction between Lipiodol and cells was studied by treating Lipiodol in a human hepatocellular carcinoma cell line(Hep) and mouse fibroblast cell line (L929). Irregular, sustained radioactivity was released from both cell lines shortly after incubation in the radioiodinated Lipiodol mixed media. Lipiodol droplets were found to be firmly attached to the cells following the incubation and these cells were strongly positive for fat stains. The radioiodinated Lipiodol demonstrated the same behavior of accumulation within the cell and on the cell membrane. Although the amount of Lipiodol attached was almost equal in both of the cell lines, the final amount accumulated in the cells was larger in the Hep cells. The accumulation of Lipiodol within the cell and on the cell membrane may play a significant role for its selective targeting and its prolonged retention in the solid tumor.

Total palmar resurfacing with scapular free flap in a 26-year contracted hand

The scapular free flap offers a large-sized and well-vascularized coverage for variable defects. It is not regarded, however, as a favorite tool for palmar resurfacing because of its bulky and rigid nature. A 28-year-old man had sustained a contact dermal injury at the age of 2 years that resulted in a severely deformed hand. The total palmar defect was resurfaced by surgical intervention with a scapular free flap. After secondary procedures, the final result was promising. The present report focuses on the secondary procedures, which make a more functional and aesthetically pleasing hand after coverage with the scapular flap. Also, our result suggests that even finger joints contracted for 26 years can recover motion if they have not been directly damaged.

Effects of glutamines and glutamates at sites of covalent modification of a methyl-accepting transducer

Chemotactic transducer proteins of Escherichia coli contain four or five methyl-accepting glutamates that are crucial for sensory adaptation and gradient sensing. Two residues arise from posttranslational deamidation of glutamines to yield methyl-accepting glutamates. We addressed the significance of this arrangement by creating two mutated trg genes: trg(5E), coding for a transducer in which all five modification sites were synthesized as glutamates, and trg(5Q), in which all five were glutamines. We found that the normal (3E,2Q) configuration was not an absolute requirement for synthesis, assembly, or stable maintenance of transducers. Both mutant proteins were methylated, although Trg(5Q) had a reduced number of methyl-accepting sites because two glutamines at adjacent residues were blocked for deamidation and thus could not become methyl-accepting glutamates. The glutamine-glutamate balance had striking effects on signaling state. Trg(5E) was in a strong counterclockwise signaling configuration, and Trg(5Q) was in a strong clockwise signaling induced by ligand binding, and alanines substituted at modification sites had an intermediate effect. Chemotactic migration by growing cells containing trg(5E) or trg(5Q) exhibited reduced effectiveness, probably reflecting perturbations of the counterclockwise/clockwise ratio caused by newly synthesized transducers not modified rapidly enough to produce a balanced signaling state during growth. These defects were evident for cells in which other transducers were not available to contribute to balanced signaling or were present at lower levels than the mutant proteins.

Intrinsic religiousness and religious coping as life stress moderators for Catholics versus Protestants

Two prospective studies were conducted to test the stress-moderating effects of intrinsic religiousness and overall religious coping on the depression and trait anxiety of Catholic and Protestant college students. Both studies found a significant cross-sectional interaction between controllable life stress and religious coping in the prediction of Catholics' depression, with religious coping serving a protective function at a high level of controllable negative events. Both studies also found a significant prospective interaction between uncontrollable life stress and intrinsic religiousness in the prediction of Protestants' depression; the relationship between uncontrollable stress and depression was positive for low intrinsic Protestants, flat for medium intrinsic Protestants, but negative for high intrinsic Protestants. The findings are discussed in terms of their implications for the role of religion in life stress adjustment.

The gastric juice urea and ammonia levels in patients with Campylobacter pylori

The authors studied gastric juice ammonia and urea nitrogen levels to determine how they are altered by gastric Campylobacter pylori (CP) infection. Patients with chronic gastritis (20), peptic ulcer (24), hepatic cirrhosis (10), chronic renal failure (13), or gastric remnant (20) were included. Endoscopic biopsy specimens stained with the Warthin-Starry stain were evaluated for the presence of CP. Blood and gastric juice analysis was performed for 11 of the patients with chronic renal failure and 37 patients from the remaining groups. CP was identified in gastric biopsies from 50 of 87 (57.5%) patients, including 87.5% with peptic ulcer and 40-50% of those with chronic gastritis, cirrhosis, chronic renal failure, or gastric remnant. CP infection had no effect on blood urea nitrogen or blood ammonia levels in any group of patients. The urea nitrogen level of gastric juice was higher in patients with chronic renal failure than in other groups but was not related to CP infection. CP infection was associated with a significant increase in gastric juice ammonia levels, both in patients with chronic renal failure (23.3 mmol/L vs. 2.90 mmol/L; [P less than 0.05]) and in other groups (5.48 mmol/L vs. 1.26 mmol/L [P less than 0.0001]). The authors conclude that elevation of gastric juice ammonia level is an indicator of gastric CP infection.

Distribution of Lipiodol in hepatocellular carcinoma

Intrahepatic distribution of Lipiodol and I-131 Lipiodol infused via the hepatic arteries was evaluated in six patients with HCC who had undergone hepatic lobectomy or segmentectomy. CT scan and gamma camera radiograph confirmed that the oily contrast material or I-131 radioactivity accumulated selectively in the tumor over a long period. One to two thirds of the tumor mass appeared necrotic, although the extent tended to be larger in the case of radioactive Lipiodol infusion. The tumor cells contained numerous lipid globules within the cytoplasm. Also, oil red 0 stain demonstrated that the individual tumor cells had non-globular lipid on their surface. In conclusion, Lipiodol leaks out of the vascular spaces to attach to the cancer cell membrane as a non-globular lipid as well as to enter the cancer cells as a globular lipid. This phenomenon specific to cancer cells suggests a biochemical membrane change which may have occurred during carcinogenesis, causing alteration of membrane transport and cell death.

Melanosis coli--histochemical and immunohistochemical comparison of the pigments of melanosis coli and Dubin-Johnson syndrome

We compared the pigment of melanosis coli with the pigment of Dubin-Johnson syndrome, melanin, and lipofuscin. The pigment of melanosis coli appeared similar to lipofuscin in that it stained positively with periodic acid-Schiff, oil red-0 and Victoria blue stains and revealed negative reactions to the immunohistochemical stains for S-100 protein and neuron specific enolase, but had similarity to melanin as shown by the positive reaction to Fontana-Masson stain and negative autofluorescence. The pigment of Dubin-Johnson syndrome showed the same histochemical and immunohistochemical characteristics as that of melanosis coli. The results indicate that the pigments of melanosis coli and Dubin-Johnson syndrome are identical and are variants of lipofuscin.

Intrinsic religiousness and religious coping as life stress moderators for Catholics versus Protestants

Two prospective studies were conducted to test the stress-moderating effects of intrinsic religiousness and overall religious coping on the depression and trait anxiety of Catholic and Protestant college students. Both studies found a significant cross-sectional interaction between controllable life stress and religious coping in the prediction of Catholics' depression, with religious coping serving a protective function at a high level of controllable negative events. Both studies also found a significant prospective interaction between uncontrollable life stress and intrinsic religiousness in the prediction of Protestants' depression; the relationship between uncontrollable stress and depression was positive for low intrinsic Protestants, flat for medium intrinsic Protestants, but negative for high intrinsic Protestants. The findings are discussed in terms of their implications for the role of religion in life stress adjustment.

Infantile myofibromatosis

We report a case of infantile myofibromatosis in a male infant with involvement of the lungs and subcutaneous tissue. We studied our case by light microscopy, immunohistochemistry and electron microscopy. The results reveal that this entity is of a myofibroblastic nature. We reviewed 165 cases including our case. We believe this is the first report in Korea of infantile myofibromatosis with pulmonary involvement.

Hamartoma of the urachal remnant

A case of urachal hamartoma occurred in the urinary bladder of a 45-year-old woman, whose presenting symptoms were frequent urination and nocturia. Computed tomographic and contrast radiologic examinations demonstrated a broad-based 5-cm polypoid mass at the dome of the bladder. Grossly the polypoid mass was smooth surfaced and covered by innocent transitional epithelium. The mass and the underlying bladder wall consisted of multiple cystic cavities of various sizes and hyperplastic smooth-muscle bundles. Light microscopy identified numerous tubuloglandular structures, most of them lined by transitional cell epithelium. Simple or ciliated columnar cells and occasional mucous cells were also present, particularly in the epithelium of cystic cavities. Some tubules had communicated with the bladder lumen. Hamartoma of the urachal remnant should be included in the differential diagnosis of urachal and bladder tumors.

The effect of combined application of argon and Nd-YAG lasers on iridectomy in rabbits

Recently iridectomy using an argon or Nd-YAG laser to treat narrow angle glaucoma has become popular, and is now the procedure of choice over the standard surgical technique. However, the shock wave of the Nd-YAG laser causes hemorrhage in almost all cases and the high energy level of the Nd-YAG laser, which is required for iridectomy, causes injury to the lens and cornea. Furthermore, there is a tendency toward closure of the iridectomy site after argon laser application. We performed iridectomies by a combined application of argon and Nd-YAG lasers in pigmented rabbits to improve iris bleeding, iridectomy patency, and lens and corneal damage. The iridectomy patency and the lens and corneal damage were examined with a scanning electron microscope. The rabbits that underwent laser iridectomies with only the Nd-YAG laser were used as a control group. Based on the results, it can be concluded that laser iridectomy by a combined application of argon and Nd-YAG lasers results in a lower rate of bleeding, a higher rate of patency, and less damage to the lens and cornea as compared with iridectomy performed by Nd-YAG laser only.

The chondrocutaneous postauricular free flap

Use of the auriculomastoid region as a donor-site for a microvascular free flap is still not the general consensus. This report presents three patients with composite tissue defects of the face aesthetically reconstructed with a chondrocutaneous postauricular free flap. For its safe surgical application, additional anatomic knowledge was refined with cadaver study. Use of the chondrocutaneous postauricular free flap has some merits. Its dissection is straightforward and safer than when only the cutaneous unit is used. It also offers a more dependable vascularized composite tissue as a one-stage operation. With freedom of design, a variable combined facial defect can be delicately reconstructed. The final aesthetic results obtained were gratifying, and the donor-site deformity was minimal.

Reverse-flow postauricular arterial flap for auricular reconstruction

Two patients with an ear defect, each reconstructed with a reverse-flow postauricular arterial flap are presented; one defect was caused by accidental exposure of bare cartilage at the posterior helix and the other by traumatic loss of earlobe. After the flaps were transposed, a line of auditory signals was dictated by Doppler probing, which suggested the presence of reverse blood flow in the flaps from the anteroauricular vessels. We believe that the reverse-flow postauricular arterial flap is a reliable and convenient optional tool in the reconstruction of auricular defects.

The short-lip deformity after triangular flap repair: a lengthening technique

A method for lengthening of the short lip after triangular-flap repair of the unilateral cleft lip is documented. This technique offers a minimal additional scar line and a maximum effect.

Scintigraphic patterns of the reflex sympathetic dystrophy syndrome of the lower extremities

Thirty-two patients with clinical signs and symptoms of the reflex sympathetic dystrophy syndrome (RSDS) of the lower extremities underwent Tc-99m MDP bone scintigraphy. Twenty-three patients had abnormal scan findings consistent with RSDS, while the scans of the remaining nine patients were normal. Of the 23 patients with abnormal scans, 19 demonstrated increased periarticular activity on early and delayed images, while 4 patients demonstrated decreased activity in the affected limb.

Adaptational "crosstalk" and the crucial role of methylation in chemotactic migration by Escherichia coli

We investigated roles of methylation in bacterial chemotaxis by characterizing a methyl-accepting transducer protein incapable of methylation because of amino acid substitutions at the modification sites. Mutant Trg protein recognized ligand and generated excitatory signals that affected flagella but was unable to mediate efficient adaptation or net cellular migration in a relevant chemical gradient. Defects caused by lack of methyl-accepting sites on Trg were suppressed by a sufficient cellular content of other transducer molecules with functional methyl-accepting sites. These observations establish directly that methylation is crucial for transducer-mediated chemotaxis and that neither phosphotransfer reactions among the soluble Che proteins nor other interaction among those chemotactic components can effectively fulfill the functions of methylation. Suppression was correlated with adaptational "crosstalk" in which unoccupied methyl-accepting transducers acquired methyl groups, thus apparently substituting effectively for blocked methyl-accepting sites on the transducer. A plausible model for this phenomenon is that increased methylation of unstimulated transducers results from global inhibition of the demethylating enzyme in a cell with a normally active methyltransferase and no available methyl-accepting sites on the stimulated, mutant transducer. Thus methylation can perform its roles in adaptation and gradient sensing even if modification occurs on molecules different from those that recognize the stimulating compound. This observation emphasizes the central role of methylation and the modular nature of the chemosensory system.

Large mononuclear cells in seminoma--an immunohistochemical analysis of 21 cases

Twenty-one cases of seminoma (including testicular seminoma, ovarian dysgerminoma and extragonadal germinoma) were reviewed for the cell types responsible for the production of alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG). Histologically the cases included seventeen classical seminomas and 4 anaplastic seminomas. The latter had some mononuclear and multinuclear giant cells. All 4 patients with anaplastic seminoma had elevated levels of serum AFP, and each of these cases contained AFP producing tumor cells identified by immunoperoxidase staining. All seminomas of patients with elevated serum levels of HCG were of the classical type but HCG producing tumor cells could not be identified by immunoperoxidase staining. Immunoreactivity to anti-AFP was found in some large mononuclear cells and anaplastic cells. To explain these results, we propose that the large mononuclear cell is a multipotential cell capable of differentiating into a germ cell, yolk sac and embryo, and that the anaplastic seminoma cells might represent a stage on the continuum of cellular differentiation from the large mononuclear cells to germ cells. The multinuclear giant cell does not appear to be essential for the production of either AFP or HCG in seminoma.

Inactivation of Acinetobacter calcoaceticus acetate kinase by diethylpyrocarbonate

Acetate kinase purified from Acinetobacter calcoaceticus was inhibited by diethylpyrocarbonate with a second-order rate constant of 620 M-1.min-1 at pH 7.4 at 30 degrees C and showed a concomitant increase in absorbance at 240 nm due to the formation of N-carbethoxyhistidyl derivative. Activity could be restored by hydroxylamine and the pH curve of inactivation indicates the involvement of a residue with a pKa of 6.64. Complete inactivation of acetate kinase required the modification of seven residues per molecule of enzyme. Statistical analysis showed that among the seven modifiable residues, only one is essential for activity. 5,5'-dithiobis(2-nitrobenzoic acid), p-chloromercuryphenylsulfonate, N-ethylmaleimide and phenylglyoxal did not affect the enzyme activity. These results suggest that the inactivation is due to the modification of one histidine residue. The substrates, acetate and ATP, protected the enzyme against inactivation, indicating that the modified histidine residue is located at or near the active site.

A new arterial flap from the postauricular surface: its anatomic basis and clinical application

We studied the arterial pattern of the postauricular surface in 16 cadavers and compared them to the results of Doppler probing in the auricles of 15 human volunteers. The dissections revealed that the postauricular surface is mainly supplied by three to five sizable branches from the upper, middle, and lower divisions of the posterior auricular artery, traversing in a rather straight and cephalic direction toward the auricular rim. One or more branches of the middle division are constantly present and distribute over the upper two-thirds of the postauricular surface. These anatomic findings were compatible with the results of the Doppler probing. We have done four auricular reconstructions with postauricular arterial flaps with excellent postoperative results. It is worthwhile to use the postauricular arterial flap in restoring the middle third of the auricle.

Fasciocutaneous V-Y advancement flap for repair of sacral defects

Sacral defects from 6 to 11 cm in diameter were closed with bilateral fasciocutaneous V-Y advancement flaps. All the defects were easily closed without any postoperative complication. We believe that the V-Y advancement technique using the fasciocutaneous unit has some major advantages for repair of moderate-size sacral defects. It is a safe, simple, and less invasive procedure.

Home birth and hospital deliveries: a comparison of the perceived painfulness of parturition

Cognitive assessments of the amount of pain associated with childbirth by parents electing either homebirth (n = 282) or hospital delivery (n = 191) were compared using Thurstone's univariate scaling method of paired comparisons. Subjects compared the pain of childbirth with 8 other painful events. The hospital birth group rated childbirth pain significantly higher than the homebirth group. In the homebirth group, females considered the pain to be less than the males, and in the hospital birth group, the females rated pain higher than the males.

Planar and SPECT Tc-99m red blood cell imaging in hepatic cavernous hemangiomas and other hepatic lesions

The utility of Tc-99m RBC imaging in the diagnosis of hepatic cavernous hemangiomas has been established. Of the 25 patients with various focal hepatic lesions evaluated, 16 were diagnosed as having hemangiomas: eight proven by surgery, two proven by angiography, and six proven by maintaining a stable clinical course ranging from 6 to 12 months with normal follow-up liver function tests. Although fourteen of these were detected by planar imaging, two were detected by SPECT only. Two patients with large hemangiomas had false-negative scans, whereas the remaining seven patients had other liver lesions.