Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells

Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin 3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin 3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer, and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing hair cells in the frog, chicken, and zebrafish.     

Immunoregulatory effects of phospholipase A2 (PLA2) on the proliferation of human lymphocytes

Extracellular phospholipase A2 (PLA2) is a proinflammatory enzyme found especially in the inflammatory exudate to modulate blood flow to areas of antigen stimulation. In this study we found that PLA2 exerted a biphasic effect on the proliferation of phytohemagglutinin (PHA)-stimulated human mononuclear cells (PHA MNC). At low concentrations range from 0.001 to 1 U/ml, PLA2 enhanced the proliferation of PHA MNC (maximal increase was 37.0 +/- 5.67%). Conversely, at concentrations over 10 U/ml, PLA2 markedly suppressed the PHA-induced MNC proliferation (maximal decrease was 88.86 +/- 2.89%). PLA2 was non-toxic to lymphocytes after three days culture, unless the concentration was higher than 100 U/ml. The membrane polarization of PHA-stimulated lymphocytes was also increased by PLA2 at a low concentration. In addition, PLA2 displayed a similar effect on the proliferation of streptokinase-streptodornase (SK/SD) or allogeneic cell stimulated lymphocytes. The change of lymphocyte proliferation by PLA2, was parallel to the change of percentage of helper T cells. Furthermore--a CD4-rich population was proved more susceptible to PLA2 effect than a CD8-rich population. Para-bromophenacyl bromide (pBPB), an irreversible inhibitor of PLA2, abrogated the biphasic effect of PLA2 on PHA MNC proliferation. These results suggest that PLA2 plays a regulatory role on immune reactions by modulating the percentage of helper T cells.     

Microvascular corrosion casting of normal tissue, transitional mucosa and adenocarcinoma in the human colon.

The microcirculatory architecture of normal tissue, transitional mucosa and adenocarcinoma of the human colon was investigated with microvascular corrosion casting (MVCC) combined with scanning electron microscopy (SEM). The study showed that the capillaries within the normal mucosa were arranged in a regular hexagonal pattern around the mucosal glands and that the microvessels of transitional mucosa mostly had lost the typical hexagonal pattern and become slightly wider in diameter. The microvessels in the tumor periphery were increased in number and disorganized, and presented large variation in morphology with claw-like formations, widened sinuses, diverticula and appendixoid patterns. Microvessels were lacking in the central areas of tumors. These morphological alterations may serve as additional indicators of tumor development.     

Hysteroscopic treatment of septate uterus with Neodymium-YAG laser.

OBJECTIVE: To determine the effectiveness of Neodymium-YAG (Nd-YAG) laser for hysteroscopic transection of the septate uterus to improve pregnancy outcome. DESIGN: Patients treated for recurrent pregnancy loss and/or infertility were evaluated for before versus after treatment pregnancy outcomes. SETTING: All patients were referred to a University Reproductive Endocrine and Infertility practice from 1986 through 1990. PATIENTS, PARTICIPANTS: Nineteen patients underwent hysteroscopic transection of uterine septa after exclusion of other factors that may cause recurrent fetal wastages and/or infertility. They were allowed to conceive 8 weeks after surgery after a postoperative hysterosalpingogram. Fourteen women attempted conception during a time span of 11 to 42 months; 3 patients declined to conceive, and 2 were lost to follow-up. INTERVENTIONS: Hysteroscopic transection of the uterine septum with a Nd-YAG laser was performed in all patients. The Nd-YAG laser delivered via a 600-microns bare fiber or an 800-microns sculpted fiber through operative hysteroscopy. MAIN OUTCOME MEASURES: To evaluate the success and complications of this new laser technique. RESULTS: (1) Thirteen patients conceived; 10 delivered a live infant at term; (2) 87% of the postoperative pregnancies were considered successful as compared with 11% preoperative; (3) complications included a small perforation of the uterus (no treatment needed) and development of uterine adhesions (1 case only). CONCLUSIONS: Hysteroscopic metroplasty with the Nd-YAG laser is a valuable alternative new technique for the treatment of uterine septum.     

Paraffinoma in the urinary bladder: CT findings.

A case of a paraffinoma in the urinary bladder is presented. Plain radiography and intravenous urography showed a low attenuation filling defect in the urinary bladder, and CT demonstrated a lobulated fat-attenuation mass floating in the urinary bladder.     

Sonographic appearance of Krukenberg tumor from gastric carcinoma

Sonographic findings in 16 cases of Krukenberg tumor from gastric carcinoma were analyzed. The patients' ages ranged from 25 to 52 years (mean 42 years). The tumor involved both ovaries in 14 patients with asymmetrical masses in 9 of 14 cases. Ascites was noted in 15 cases. Echogenicity of the tumor varied from solid to predominantly cystic: solid in 8, mixed in 6, and predominantly cystic in 2 cases. Solid masses tended to be smaller than mixed or cystic masses. The primary gastric carcinoma had been diagnosed before emergence of the tumors in only 7 cases. The findings suggest that in relatively young patients with ovarian mass, particularly bilateral tumors, careful evaluation for gastrointestinal tract involvement should be done.     

Benign osteoblastoma of the occipital bone: Case report and literature review

We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation.     

Huge gastric diospyrobezoars successfully treated by oral intake and endoscopic injection of Coca-Cola

A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.