Carbon nanowall-based gas sensors for carbon dioxide gas detection.

Carbon nanowalls (CNWs) have attracted significant attention for gas sensing applications due to their exceptional material properties such as large specific surface area, electric conductivity, nano- and/or micro-porous structure, and high charge carrier mobility. In this work, CNW films were synthesized and used to fabricate gas sensors for carbon dioxide (CO2) gas sensing. The CNW films were synthesized using an inductively-coupled plasma (ICP) plasma-enhanced chemical vapor deposition (PECVD) method and their structural and morphological properties were characterized using Raman spectroscopy and electron microscopy. The obtained CNW films were used to fabricate gas sensors employing interdigitated gold (Au) microelectrodes. The gas sensors were fabricated using both direct synthesis of CNW films on interdigitated Au microelectrodes on quartz and also transferring presynthesized CNW films onto interdigitated Au microelectrodes on glass. The CO2gas-sensing properties of fabricated devices were investigated for different concentrations of CO2gas and temperature-ranges. The sensitivities of fabricated devices were found to have a linear dependence on the concentration of CO2gas and increase with temperature. It was revealed that devices, in which CNW films have a maze-like structure, perform better compared to the ones that have a petal-like structure. A sensitivity value of 1.18% was obtained at 500 ppm CO2concentration and 100 °C device temperature. The CNW-based gas sensors have the potential for the development of easy-to-manufacture and efficient gas sensors for toxic gas monitoring.

[A new minimally invasive procedure for the conservative treatment of uterine prolapse--the posterior IVS].

BACKGROUND: The risk of women who undergo surgery for the treatment of pelvic organ prolapse (POP) by the age of 80 is reported to exceed 10%, and is expected to rise with the increase in life expectancy. Most women affected are in their 5th or 6th decade, and the majority will suffer other medical problems. The current medical literature asserts that the vaginal surgical approach for POP operations are followed by less complications and provide a shorter rehabilitation period than the abdominal route. Hysterectomy is widely accepted as part of POP reconstructive surgery whenever the uterus is significantly prolapsed, however, there is no clear evidence to support the role of hysterectomy in improving surgery outcome. We present our experience with a new minimally invasive procedure - the posterior intravaginal slingplasty (IVS) for utero-suspension in the presence of moderate and advanced uterine prolapse. AIM: To evaluate the feasibility, intra- and post-operative complications and short term results of the posterior IVS procedure and uterosuspension for uterine prolapse. METHODS: Reconstructive surgery using the posterior IVS was performed on 18 women with moderate to severe uterine prolapse who chose to preserve their uterus. Patients were then followed 1,6,12 months and 2 years post-operatively to assess any recurrence of pelvic organ prolapse. RESULTS: No major intra- or post-operative complications were reported. Follow-up of one to 13 months showed good results. CONCLUSIONS: Reconstructive POP surgery may not necessitate hysterectomy. The posterior IVS is a novel safe, minimally invasive, simple and effective surgical procedure for the treatment of POP, permitting uterine preservation. A larger number of patients and a longer follow-up period are required for proper evaluation of the actual safety and efficacy of this procedure.

Is the unique negatively charged polypeptide of crayfish yolk HDL a component of crustacean vitellin?

The yolk protein of Cherax quadricarinatus contains six major high-density lipoprotein (HDL) subunits with the approximate molecular masses of 177, 155, 106, 95, 86, and 75 kDa, of which only the 106-kDa polypeptide is negatively charged. On the basis of their molecular weights, time of appearance and disappearance, their floating density and susceptibility to enzyme degradation (by a serine proteinase), these six HDL polypeptides were classified into two subgroups. One group comprises the higher-molecular-weight compounds above 106 kDa, and the other includes the lower-molecular-weight compounds up to 95 kDa. Other than being different from the lower-molecular-weight polypeptides, the negatively charged 106-kDa polypeptide was significantly different from members of its higher-molecular-weight group belonging to a different, less abundant, yolk protein as shown by HPLC separation. Immunological studies and peptide mapping in which the 106-kDa polypeptide did not show similarity to any of the other HDL components confirmed these differences. Moreover, the amino acid composition of the 106-kDa polypeptide was different from that of known vitellin from other crustacean species. This unique negatively charged polypeptide presents an enigma as it is known to be a secondary vitellogenic-related HDL polypeptide, immunolocalized in yolk globules; however, it is different to all the other HDL polypeptides, thus presenting the question whether it is indeed a component of "classical" crustacean vitellin.

Effects of implantation of hypertrophied androgenic glands on sexual characters and physiology of the reproductive system in the female red claw crayfish, Cherax quadricarinatus.

The role of the androgenic gland (AG), an organ unique to male Crustacea, in the development of sex characters and physiology of the reproductive system has not been fully documented in the red claw crayfish, Cherax quadricarinatus. To investigate the role of the AG in this species, the effect of implanting hypertrophied AGs into immature female animals was followed. Of the female animals with AG implants, 91.6% developed male-like propodi, including the red patch characteristic of males of this species. The development of female secondary sex characteristics such as a wider abdomen, a wider endopod, and simple setation was inhibited. At the end of the experiment, the ovaries of the AG-implanted females contained mostly lipid-stage oocytes, with a small number of oocytes at the early yolk stage. The gonadosomatic index of the AG-implanted females was significantly lower than that of the control (sperm duct-implanted or sham-operated) females, which had mature oocytes with a well-defined perinuclear zone and yolk globules. An immunohistochemical test using an antibody developed against a 106-kDa secondary vitellogenic polypeptide showed only slight immunoreactivity in the oocytes of AG-implanted females compared with abundant immunoreactivity in control ovaries. In the polypeptide profile of the high-density lipoprotein (HDL) from the hemolymph of AG-implanted females, the 206- and 79-kDa secondary vitellogenesis-specific polypeptides were not found, whereas they were present in the profile of control females. In contrast, the female-specific 177-kDa polypeptide was present in the polypeptide profile of hemolymph HDL of both AG-implanted females and control females. It seems therefore that while secondary sex characters were masculinized under the influence of the implanted AG, the process of vitellogenesis was suppressed but not fully eliminated in the AG-implanted females.

Congenital epulis.

Epulis is a rare tumor of the newborn, also known as granular cell tumor of the newborn or Neumann's tumor. This tumor arises from the mucosa of the gingiva, most commonly from the anterior part of the maxillary alveolar ridge, and is typically seen as a mass protruding out of the newborn child's mouth, which may interfere with respiration or feeding. Epulis is seen only in the newborn and is a different entity from other granular cell tumors. The tumor has a marked female preponderance of 8:1. The recommended treatment is prompt surgical resection. Recurrences of the tumor and damage to future dentition have not been reported, suggesting that radical excision is not warranted. A newborn female with such a mass is described. The tumor was resected using a carbon dioxide laser; the postoperative course was uneventful. On histologic examination, it was composed of diffuse sheets and clusters of polygonal cells containing small round to oval nuclei and abundant coarsely granular cytoplasm. The tumor cells stained positive for vimentin, and negative for S100-protein, actin, desmin, laminin, keratin, estrogen, and progesterone receptors. Electron microscopic examination showed granular cells containing heterogeneous electron-dense granules, lysosomes, and cytoplasmic lipid droplets. The clinical and microscopic features of such tumors are reviewed.

High-density lipoprotein associated with secondary vitellogenesis in the hemolymph of the crayfish Cherax quadricarinatus.

The high-density lipoproteins LPI and LPII were isolated from the hemolymph of the crayfish Cherax quadricarinatus by gradient ultracentrifugation and high-performance liquid chromatography (HPLC). Both lipoproteins contained a carotenoid moiety. LPI is comprised of a single polypeptide with an approximate molecular mass of 96 kDa. LPII was composed of two similar native components, LPIIa and LPIIb, both having polypeptides of 80 and 177 kDa. Both under natural conditions and after endocrine manipulations, LPI was present in males and in females, regardless of the female reproductive stage. LPII was present only in secondary-vitellogenic females, but not during the winter reproductive arrest period. LPII was also absent from young females that had received androgenic gland implants. LPII also appeared in the hemolymph of intersex individuals from which the androgenic gland had been removed. It is therefore suggested that LPII serves as a marker indicating the onset of secondary vitellogenesis in C. quad'iariicarintus females.

Harvesting large fascia lata sheaths: a rational approach.

This article describes an "S"-shaped incision for the open approach of harvesting wide sheets of fascia lata with reference to the important anatomical landmarks. Forty-three patients required dural replacement in cases of tumors, trauma, or cerebrospinal fluid leak involving the anterior skull base. The extended anterior suberanial approach to the skull base was used for all patients. Early functional status of the operated limb in seven of the patients treated first was assessed by physical examination and then by means of the computerized Kinetic Communicator (Kin-Com; Medex Diagnostics, Canada) dynamometer. None of these patients suffered any significant immediate complications and had good results at the preliminary functional assessment. All other patients were evaluated clinically for functional deficits of the operated lower limb to further assess its morbidity. The technique described herein was shown to enhance the case and control of fascia lata harvesting. It affords low complication rate and donor limb morbidity. Donor limb morbidity did not have any deleterious effect on the patients' normal daily activities and only became apparent during strenuous physical activity.

A newly established ELISA showing the effect of the androgenic gland on secondary-vitellogenic-specific protein in the hemolymph of the crayfish Cherax quadricarinatus.

A quantitative enzyme-linked immunosorbent assay (ELISA) was developed to monitor the onset of secondary vitellogenesis in Cherax quadricarinatus females and in intersex individuals (having both male and female reproductive systems) after removal of the androgenic gland (AG). As a prerequisite for the assay, the 106-kDa polypeptide was separated from newly laid C. quadricarinatus eggs by SDS-PAGE, and anti-106-kDa antibody was raised in rabbit. The specificity of the anti-106-kDa polypeptide for proteins specific for the hemolymph of secondary-vitellogenic females was confirmed by double immunodiffusion and immunoblot cross-reactivity tests. A characteristic standard ELISA curve, using egg high-density lipoprotein (HDL), showed linearity between 16 and 500 ng (r = 0. 953) and was sensitive for amounts as low as 8 ng. The inter- and intraassay coefficients of variance were 14.8 and 7.2%, respectively. Only traces of egg HDL equivalents were detected in the hemolymph of male and primary-vitellogenic females (11 to 110 microg/ml), confirming the specificity of the assay, whereas high levels of such a protein (8-35 mg/ml) were detected in the hemolymph of secondary-vitellogenic females. Removal of the AG from intersex individuals leads to a significant increase in the concentration of vitellogenic-specific protein in the hemolymph (up to 2 mg/ml). Moreover, a significantly lower concentration was found in females subjected to AG transplant (79.3 microg/ml). The ELISA thus provided an accurate and sensitive tool to investigate the influence of the AG on the expression of a vitellogenic-specific protein in female and intersex C. quadricarinatus, confirming the central role of this gland in tuning sexual plasticity in this species.

Early outcome and complications of the extended subcranial approach to the anterior skull base.

OBJECTIVES: To present the technique of the extended subcranial approach to the anterior skull base and to review the results in 55 patients who underwent the procedure. STUDY DESIGN: Retrospective review of the records of 55 patients who underwent the extended subcranial approach to the anterior skull base between 1994 and 1998 for the treatment of various neoplasms originating in the nasal cavity, nasopharynx, paranasal sinuses, orbit, or meninges, as well as for the repair of complex craniofacial trauma and/or cerebrospinal fluid (CSF) leak. Preoperative patient evaluation and the surgical technique are also reviewed. METHODS: Patient records were retrospectively reviewed and tabulated for age, sex, and indications for procedure, with special focus on early outcome and complications. RESULTS: Twenty-six patients underwent oncologic resections, 22 patients had reduction of complex fronto-naso-orbital and skull base fractures, and seven patients had repair of CSF leak. Significant complications in the oncologic group consisted of one hematoma requiring needle aspiration and two cases of temporary nontension pneumocephalus. In the fracture group, one patient died because of extensive intracerebral damage and multiorgan failure, and one patient had nontension pneumocephalus coupled with CSF leakage and one patient had temporary nontension pneumocephalus. The most common late complication in all three groups was anosmia. CONCLUSIONS: Based on their review, the authors conclude that the extended subcranial approach to the anterior skull base is a safe, versatile, and effective procedure for the surgical treatment of various pathological conditions involving the anterior skull base.

Lymphangioma circumscriptum.

Two children with lymphangioma circumscriptum (LC), a rare cutaneous lymphangioma, are described. One was diagnosed antenatally as having a right axillary cystic hygroma; in addition, postnatally LC was noted on the right forearm. A few years later a mediastinal lymphangioma was diagnosed. This combination of LC associated with additional malformations of the lymphatic system has not been reported previously, and may point to a generalized developmental disorder of the lymphatic system. The pathophysiology of the lesion is discussed with a review of the pertinent literature. It appears that LC primarily affects the subcutaneous tissue in the form of cystic dilatation of lymphatic channels without systemic lymphatic communication. The skin lesions are probably secondary to the increased intraluminal pressure. The typical clinical appearance is manifested by multiple skin vesicles and lymphorrhea. The main treatment modality is surgical excision. Recurrences are not unusual and require re-excision.

The role of the gastrocnemius muscle flap in limb-sparing surgery for bone sarcomas of the distal femur: a proposed classification of muscle transfers.

Limb-sparing surgery for bone and soft-tissue sarcomas involves three phases: (1) resection of the tumor with free margins, (2) reconstruction of the bone and joint defect, and (3) reconstruction of the soft tissues. This presentation focuses on the third phase. Between January of 1988 and January of 1994 we performed 33 distal femoral resections, 32 for malignant and 1 for benign tumors. There were 19 men and 14 women aged from 6 to 78 years (mean age 28 years). Twenty-seven patients had gastrocnemius muscle flap transfers, 24 having "primary" transfers and 3 having "secondary" transfers. The lateral gastrocnemius muscle was used in 18 patients, the medial in 8 patients, and both in 1 patient. We propose a classification of the transfers based on the size of the soft-tissue defect above the prosthesis needing coverage and the length of the neurovascular bundle of the muscle. Twenty-six of the 27 muscles survived; one patient had necrosis of the skin and muscle. Two patients had persistent sinuses at the scar that were managed successfully (one of them was before a secondary muscle transfer). Six patients did not have gastrocnemius muscle flap transfers. Two of them had persistent sinuses for years, and one patient had titanium "synovitis" and needed repeated operations including removal of the prosthesis and revision. The particular vascularization of the gastrocnemius muscle (one pedicle at the level of the knee joint) situated close to its origin, the size of the muscle belly, and the fact that it is situated in the dissection field and its transfer does not affect the function of the spared limb make it particularly suitable for the coverage of wide areas of skin and muscle loss at the knee region. In the classification that we propose, type I is reserved for coverage of small areas, while types II and III are used for coverage of larger areas. Flap transfer should be performed primarily at the time of the resection in order to avoid complications of wound healing and to reduce delays in chemotherapy protocols.

A simple, rapid, reproducible tie-over dressing.

A simple and quickly performed technique for the construction of tie-over dressings is described. After adjustment of the graft to the skin defect, skin staples are used to tack simultaneously the graft and looped silk threads circumferentially. Securing the threads is achieved by using a shortened disposable syringe cylinder through which the threads are passed and held in place by the adjusted piston. A stable fixation is easily achieved in all cases using one or more of these devices depending on the size of the defect. This technique enables the subsequent application of the dressing if needed.

Intersex Red Claw Crayfish, Cherax quadricarinatus (von Martens): Functional Males with Pre-vitellogenic Ovaries.

Intersex individuals, possessing both male and female genital openings, were assessed in two groups-7 and 19 months old-of Australian red claw crayfish (Cherax quadricarinatus). All intersex individuals investigated were functional males, as suggested by their malelike morphology and the presence of testes, sperm ducts, androgenic glands, and viable spermatozoa. When an ovary was present in an intersex individual from either group, the gonadosomatic index, the diameter of the oocytes, and the ovarian cytosolic polypeptide profile were similar to those of immature, pre-vitellogenic females. We conclude that intersexuality in C. quadricarinatus does not indicate a case of protandric sequential hermaphroditism, as previously suggested. The case of intersexuality described here presents a unique model for the study of the role of the androgenic gland in the regulation of sex differentiation in crustaceans.

Prostaglandin E2 in previtellogenic ovaries of the prawn Macrobrachium rosenbergii: synthesis and effect on the level of cAMP.

Eicosanoids are thought to play a role in the regulation of invertebrate reproduction, as they do in vertebrate systems. This was investigated using the previtellogenic ovary of the freshwater prawn Macrobrachium rosenbergii as a biological model. Concentrations of prostaglandin E2 (PGE2), assessed by means of radioimmunoassay, in the previtellogenic ovary (oocyte diameter 20-40 microns) were 32.4 +/- 14.1 pg/mg ovary. Preincubation of the ovary with indomethacin (10 microM) inhibited PGE2 synthesis by 43%. In addition, if indomethacin was added to the culture medium, cAMP levels decreased by 48%. When previtellogenic ovaries were incubated in vitro with PGE2 (0.05 micrograms/ml medium and up), cAMP levels in the tissue homogenate sharply increased. The levels of cAMP rose most significantly (up to 10-fold) when 1-10 micrograms PGE2/ml medium was applied. These results suggest that PGE2, and possibly other prostaglandins, may play a role in the endocrine regulation of crustacean reproduction.

Gigantic lipomas.

Two cases of unusually giant lipomas--weighting 5070 and 4000 gm--are described. Tumors were present for 5 years on the back in a 55-year-old man and for 20 years at the anterior compartment of the thigh in an 80-year-old woman. Difficulty in fitting clothes was the first patient's sole complaint, and social pressure was actually the reason that brought him to his doctor. The second patient suffered from pain during the last 2 years. The weight of the bigger tumor was calculated preoperatively from the uptake of technetium-99m DTPA during scanning. Dissection of the tumors from the surrounding tissues was extremely easy in both cases. At 5 years and 1 year following surgery, there is no evidence of recurrence.

Metastatic malignant melanoma with spontaneous and complete regression of the primary lesion. Case report and review of the literature.

BACKGROUND: Spontaneous regression of malignant melanoma is characterized by a partial or complete disappearance of the neoplasm. Partial regression of melanoma has been documented in large series, but complete regression is reported as occurring only sporadically. OBJECTIVE: To describe a case of metastatic malignant melanoma where the primary lesion underwent spontaneous and complete regression and to review the literature pertaining to regression of melanoma. METHODS: The patient was examined clinically. Wide excision of the skin with the lesion was performed as well as left inguinal lymph node dissection. RESULTS: Histologic examination of the lesion revealed complete regression of malignant melanoma. Examination of the lymph node dissected from the adjacent inguinal area revealed matastatic melanoma. CONCLUSIONS: Greater attention should be devoted to identification of regression in melanoma, clinically and histologically, evaluating the prognostic implications which regression might indicate.

Hand metastasis from renal cell carcinoma with no bone involvement.

Hand metastases account for 0.1% of all metastases and most of them involve primarily the bones. A case of a metastasis from renal cell carcinoma to the distal segment of the little finger with no bone involvement is described. In view of the fact that the kidneys are the origin of only 10% of hand metastases, such a case is extremely rare.

Radionuclide imaging of soft tissue masses with Tc-99m DTPA.

A scintigraphic study was carried out on 48 patients presenting with palpable soft tissue masses. Imaging was carried out using Tc-99m DTPA in three phases (dynamic, blood pool after 5 minutes, followed by late scans after 2 hours). The resultant uptake of the agent was categorized as consistently positive (14 cases), initially positive but progressively negative (7 cases), initially negative but progressively positive (7 cases), and consistently negative (20 cases). Histopathologic examinations were carried out for all cases following biopsy. A variety of malignant and benign masses were found to localize DTPA, whereas all masses that did not concentrate the agent were proven to be lipomas. In order to determine whether the uptake of DTPA bore any relationship to blood flow, additional studies using Tc-99m labeled red cells were carried out on 15 patients with soft tissue tumors. There was no correlation between blood flow or pooling and the degree of Tc-99m DTPA uptake by the palpable masses. The sensitivity of DTPA uptake as indicative of nonlipomatous tissue was 100%, and its specificity was 91%. The predictive probability that a lesion was a liopoma if there was no DTPA uptake at any phase was 100%.

Stitch removal from hair-bearing areas: a simple method.

A simple method to ease the removal of stitches in hair-bearing areas is presented. The method consists of applying a depilatory cream to remove the masking hair.