A biochemical and cytochemical study of adenosine triphosphatase activity in the phloem of Nicotiana tabacum.

A biochemical and cytochemical study has been made of the distribution of ATPase in mature and differentiating phloem cells of Nicotiana tabacum and of the substrate specificity and effects of fixation on enzyme activity. Homogenates of unfixed leaf midveins and midveins fixed in formaldehyde-glutaraldehyde were assayed for enzyme activity by determining the amount of P(i), liberated per milligram of protein from various substrates in a 30 min period at pH 7.2. In fresh homogenates, hydrolysis of ATP was not significantly different from that of ITP, CTP, and UTP. Hydrolysis of GTP was slightly higher than that of ATP. ATP hydrolysis by fresh homogenates was 17% more extensive than that of ADP, 76% more extensive than that of 5'-AMP, and was inhibited by fluoride and p-chloromercuribenzoate (PCMB). There was little or no hydrolysis of the competitive inhibitors 2'- and 3'-AMP nor with the alternate substrates p-nitrophenylphosphate (PNP) or beta-glycerophosphate (beta-GP). In homogenates of material fixed in formaldehyde-glutaraldehyde for 1(1/4) h, ATPase activity was 13% preserved. Hydrolysis of ATP by fixed homogenates was not significantly different from that of ADP, 5'-AMP, ITP, CTP, and GTP. Hydrolysis of UTP was lower. Fluoride and PCMB inhibited fixed ATPase activity. The results of cytochemical localization experiments using a lead phosphate precipitation technique were in agreement with the biochemical results. Similar localization patterns were obtained with the nucleoside triphosphates ATP, CTP, GTP, ITP, and UTP. Activity was also localized with ADP and 5'-AMP but not with the competitive inhibitors 2'- and 3'-AMP, nor with PNP or beta-GP. Little or no reaction product was deposited in other controls incubated without substrate or with substrate plus fluoride, PCMB, or N-ethylmaleimide. ATPase activity was demonstrated chiefly at the plasma membrane of mature and differentiating phloem cells and was associated with the P-protein of mature sieve elements. It is suggested that the phloem transport system derives its energy from the demonstrated nucleoside triphosphatase activity.

Rabbit allergens: a significant risk for allergic sensitization in subjects without occupational exposure.

BACKGROUND: Although rabbits are becoming popular as pets, data about the characteristics of allergic sensitization to rabbit allergens in patients without professional exposure are scarce. AIMS OF THE STUDY: To determine the characteristics of allergic sensitization to pet rabbits, and the role of direct and indirect exposure to rabbits and rabbit allergens in non-professionally exposed patients. METHODS: From among 1124 consecutive outpatients, we selected all subjects with an immediate skin reaction to rabbit dander. A clinical history including a careful evaluation of the modality of rabbit exposure, the results of skin-prick tests (SPTs) and total/specific IgE antibodies were recorded. The prevalence of rabbit ownership in the Naples area was also calculated. RESULTS: Among 753 SPT-positive patients, 20 (2.65%) were sensitized to rabbit dander (5 patients were mono-sensitized). Fifteen patients reported direct rabbit contact (7 were rabbit owners and 8 had occasional contact outside the home); 3 patients had indirect exposure through contact with rabbit owners and 2 patients denied any direct or indirect exposure. Rabbit mono-sensitized owners of pet rabbits had persistent (moderate-severe) symptoms. The prevalence of rabbit ownership is 1.56%. CONCLUSIONS: In susceptible not professionally exposed individuals, direct rabbit contact and, in some cases, indirect or no apparent exposure, may induce allergic sensitization to rabbit allergens. A progressive increase in rabbit sensitization (also by indirect exposure) may be expected as a consequence of the increase in rabbit ownership.

Gene therapy for the treatment of malignant brain tumors with in vivo tumor transduction with the herpes simplex thymidine kinase gene/ganciclovir system.

Murine retroviral vectors can infect a wide variety of proliferating mammalian cell types (e.g. lymphocytes). Non-proliferating tissues (e.g. neurons) are not transduced by murine retroviral vectors. These findings suggest that this type of vector may be useful for the selective introduction of genes into growing tumors in the brain, since the tumor is essentially the only tissue that will integrate and express the vector genes.

Coexistent empty sella and prolactin-secreting microadenoma.

The empty sella turcica may be found in people with no antecedent history of intracranial disease, as well as in those with known pituitary pathology or following therapy to the pituitary gland. We have evaluated 3 women with galactorrhea and hyperprolactinemia, 2 of whom had amenorrhea. Each had an empty sella. In all cases polytomograms demonstrated asymmetry of the sella floor with focal bony erosion, conventional pneumoencephalography showed intrasellar air, and polytomographic pneumoencephalography confirmed air limited to one side of the pituitary fossa with tumor and/or residual normal tissue on the opposite side. In 2 patients who had extensive endocrine evaluation, pituitary function was normal with the exception of hyperprolactinemia. Transsphenoidal excision of microadenomas resulted in postoperative normalization of the serum prolactin concentration and resumption of regular menses in the previously amenorrheic women.

Pupil cycle time in optic nerve compression.

We measured pupil cycle time before and after treatment in 11 patients with compressive optic nerve disease. Nine patients had chiasmal tumors and two had optic neuropathy of Grave's disease. Pupil cycle time before treatment was abnormal in at least one eye of all patients and in each case, pupil cycle time improved or worsened in accordance with the response to treatment of the patient's visual acuity and visual fields. This suggests that the pupil cycle time may be used as a simple objective office test for following up patients with impaired optic nerve conduction as the result of optic nerve compression. This information is similar to that gained from visual evoked response and may be used together with other objective clinical data such as disk pallor, nerve fiber loss, and relative afferent pupillary defect.

Severe systemic allergic reaction induced by accidental skin contact with cow milk in a 16-year-old boy. A case report.

The symptoms of food allergy are rarely induced by skin contact. A 16-year-old boy was referred to our Allergology Centre after an episode of systemic symptoms triggered by accidental skin contact with a drop of cow milk (CM) dripped from a sandwich containing fresh cheese. The patient had been allergic to CM from the age of 24 months and had experienced several episodes of urticaria-angioedema after the ingestion of tiny or "hidden" amounts of CM proteins. In vivo and in vitro diagnostic procedures showed intense sensitisation to all CM proteins (1/100 dilutions of allergenic extracts produced large wheals, and class 4 specific IgE antibodies. Total IgE antibodies were elevate (770.0 UI/). A moderate degree of bronchial hyperresponsiveness was found (PC20 metacholine: 3.90 milligrams). This case report suggests that patients with a high degree of sensitisation to CM proteins should be alert to the danger of skin contact and should beware of "hidden" CM allergens.

Radiographic diagnostic evaluation and surgical treatment of multiple cerebellar, brain stem, and spinal cord hemangioblastomas.

Multiple hemangioblastomas of the central nervous system present a greater challenge in their diagnosis and treatment than do single hemangioblastomas of the cerebellar hemisphere. Improved radiographic techniques of tomographic vertebral angiography and computed axial tomography (CT) are of considerable value in the diagnosis of multiple cerebellar, brain stem, and spinal cord hemangioblastomas. Microsurgical techniques now allow for total operative removal of many of these lesions. A case report is presented to emphasize the radiographic diagnostic evaluation as well as the microsurgical technique for removal of multiple central nervous system hemangioblastomas.

Scintigraphic, sonographic, and histologic evaluation of renal autotransplantation in cats.

OBJECTIVE: To determine scintigraphic, sonographic, and histologic changes associated with renal autotransplantation in cats. ANIMALS: 7 adult specific-pathogen-free cats: 5 males, 2 females, 1 to 9 years old. PROCEDURE: Renal autotransplantation was performed by moving a kidney (5 left, 2 right) to the left iliac fossa. Before and at multiple times after surgery, for a total of 28 days, cats were evaluated by B-mode and Doppler ultrasonography, scintigraphy, and renal biopsy. RESULTS: By 24 hours after surgery, a significant decrease (42%) in mean glomerular filtration rate (GFR) and an increase in mean renal size (81% increase in cross-sectional area) were evident in the transplanted kidney, compared with preoperative values. By postsurgery day 28, reduction in GFR was 23%. Significant changes in renal blood flow velocity were identified in both kidneys. Consistent changes in resistive index or pulsatility index for either kidney could not be identified. When all postoperative histologic data were combined, the histologic score, indicating degree and numbers of abnormalities detected, for the transplanted kidney was significantly higher than that for the control kidney. CONCLUSIONS: Significant changes in renal function, size, and histologic abnormalities develop secondary to acute tubular necrosis in cats after uncomplicated renal autotransplantation. CLINICAL RELEVANCE: Evaluation of renal size and function may be of benefit for clinical evaluation of feline renal transplant patients, whereas measurement of the resistive index may be of little clinical value.

Mechanisms and characteristics of airway sensitization to indoor allergens.

The increasing prevalence of allergic respiratory diseases, and particularly of bronchial asthma, has been linked to changes induced by human activities in outdoor and indoor environments. People living in industrialized countries spend most of their time indoors: in private homes, offices and means of transport. Indoor environments are not a refuge from outdoor air pollution. Modern systems for energy saving such as insulated windows and doors reduce the indoor natural ventilation and consequently increase the rate of indoor humidity. These conditions may determine an increase in the level of indoor pollutants (tobacco smoke, gases produced by cooling processes etc.) and of allergens derived from mites, domestic animals and cockroaches. Upholstered furniture, wall-to-wall carpets, central heating systems and/or humidifiers may also contribute to the growth of mite populations. The increasing levels of exposure to pollutants and allergens in indoor environments represents a risk factor for the development of airway sensitization, especially if these materials are inhaled early in life. The major cat allergen Fel d 1 is considered an ubiquitous allergen, since it has been found in many indoor environments where a cat has never been kept. The clothing of cat owners seems to help spread Fel d 1 in cat-free environments. Sensitization to cockroach allergens is very common in patients living in urban areas where unhygenic conditions may favour the growth of cockroach populations. Monitoring of the levels of allergens and strategies of allergen and pollutant avoidance in indoor environments are the main ways to reduce the prevalence of respiratory allergies induced by these materials.

Working towards healthy air in dwellings in Europe.

Poor indoor air quality has been implicated in the increase in allergic and respiratory diseases seen in industrialized countries in recent decades. Although air pollution in the workplace is well studied, much less is known about the consequences of poor air quality in homes. In an attempt to halt or slow down the increase in allergic and respiratory diseases, the European Federation of Allergy and Airways Diseases Patients Associations (EFA) carried out the EU-funded project entitled 'Towards Healthy Air in Dwellings in Europe' (THADE). The aims were to: compile an overview of evidence-based data about exposure to indoor air pollution and its health effects, particularly in relation to allergies, asthma and other respiratory diseases such as chronic obstructive pulmonary disease; review cost-effective measures and technology to improve indoor air quality; review legislation and guidelines on indoor air pollution; produce maps of pollutants in dwellings; and recommend an integrated strategy that defines appropriate indoor air quality policies for implementation in Europe. This paper summarizes the information about air quality in dwellings and indoor environment-related diseases collected by expert consultants within the framework of THADE and terminates with recommendations for actions aimed at improving air quality in homes. The results of this project confirmed that air pollution in dwellings is a relevant health problem. It is a complex problem that must be addressed at European and international levels, and it involves the medical profession, scientific societies, patients' organizations, lawmakers, architects and the building industry. The complete THADE report is available at http://www.efanet.org/activities/documents/THADEReport.pdf.

Adenosine triphosphatase in the phloem of Cucurbita.

The distribution of adenosine triphosphatase (ATPase) activity in the phloem of petioles and minor veins of Cucurbita maxima has been studied using a lead phosphate precipitation procedure. ATPase activity was localized in sieve elements, companion cells and parenchyma cells. Activity was found at the cell surfaces, associated with the dispersed P-protein of mature sieve elements, in mitochondria, sieve-element reticulum, and at specific regions of the cell walls. It is suggested that the ATPase at the phloem cell surfaces may function in intercellular transport of assimilates or ions, and that the ATPase activity associated with the P-protein may function in the translocation process or in callose deposition.

Reflex bradycardia during TMJ arthroscopy: case report.

A case of bradycardia occurring during TMJ arthroscopy is presented. A similar case of the TVR has not previously been reported. This reflex must be recognized by oral and maxillofacial surgeons who perform arthroscopy.

Chromophobe adenoma manifesting as a nasopharyngeal mass.

A 64-year-old woman had a sphenoid sinus tumor and nasopharyngeal mass verified to be a nasopharyngeal chromophobe adenoma with no evidence of sellar enlargement or involvement. The possibility that this mass arose from ectopic hypophyseal tissue located in the pharynx is proposed.

Locked-in syndrome caused by a solitary pontine abscess.

The clinical and pathological findings in a patient with locked-in syndrome caused by a solitary pontine abscess are reported for the first time. Successful treatment of brainstem abscess rests on early and accurate diagnosis.