Deficits in reproductive behavior in diabetic female rats are due to hypoinsulinemia rather than hyperglycemia

These studies determined whether deficits in reproductive behavior observed in streptozotocin (STZ)-induced diabetic female rats are caused by hyperglycemia or loss of insulin. Female Sprague-Dawley rats were ovariectomized and made diabetic by a single ip injection of STZ (75 mg/kg). Reproductive behavior was measured 12 days after the onset of hyperglycemia following the injection of estrogen and progesterone in doses known to restore reproductive behavior in nondiabetic rats. Rats in which STZ produced diabetes showed significantly reduced receptive and proceptive sexual behaviors. Normalization of blood glucose levels either by restricting diet or by phlorizin treatment failed to restore reproductive behavior in diabetic animals. However, even doses of insulin which were not fully effective in correcting peripheral hyperglycemia were able to prevent the STZ-induced behavioral deficit. No changes in general activity were observed in any experimental group as assessed by open field activity. The density of the norepinephrine transporter, as measured by [3H]nisoxetine binding, was reduced in the cortex but not in the brain stem, hypothalamus, or hippocampus of diabetic animals. Insulin treatment prevented the loss of cortical [3H]nisoxetine binding, and even partial normalization of blood glucose restored cortical [3H]nisoxetine binding to control levels. These findings suggest that diabetes-induced reproductive deficits are due to hypoinsulinemia and cannot be corrected simply by the normalization of blood glucose, whereas reductions in the density of cortical norepinephrine transporter result from hyperglycemia.

Characterization of the allergen Der f 7 from house dust mite extracts by species-specific and crossreactive monoclonal antibodies

BACKGROUND

The group 7 mite allergens react with IgE in 50% of sera from allergic patients.

OBJECTIVE

To determine the molecular and antigenic characteristics and heterogeneity of Der f 7 in mite extracts.

METHODS

Monoclonal antibodies (MoAbs) produced from mice immunized with recombinant Der f 7 were examined for crossreactivity to Der p 7 and then used for immunoblotting of 1 and 2-D gel electrophoresis. Deglycosylation was studied with N-glycosidase-F and N-terminal sequencing by Edman degradation. The epitopes of the monoclonal antibodies were compared by cross-inhibitory immunoassays.

RESULTS

Immunoblotting of D. farinae extracts with all the anti Der f 7 MoAbs showed major reactivities at 31, 30 and 25 kDa. The strongest immunostaining was at 25 kDa which contrasted with Der p 7 where the 31 and 30 kDa bands were strongest. The relative strength of staining however varied between extracts. The 31 and 30 kDa components were glycosylation products of the 25 kDa form which had the N-terminal sequence predicted from cDNA analysis. Two MoAbs stained an 18 kDa band consistent with a degradation product. The 2-D gels showed that different components with pIs from 5.6-6.4. Both species-specific and Der p 7 crossreactive MoAbs were produced and a two-site ELISA assay for detecting group 7 allergen was developed with MoAbs recognizing different epitopes.

CONCLUSIONS

Der f 7 has been defined by its natural N-terminal sequence and MoAbs. It apparently exists as different glycosylation and degradation products in mite extracts, the relative abundance of which differs with different preparations. A two-site ELISA to measure the allergen was developed.

Highly successful long-term outcome of kidney transplantation in Chinese recipients: an enhancing race effect?

We report on 352 cadaveric kidney transplants and 294 living related transplants performed over a 25-yr period among the Chinese population of Hong Kong. There is a marked preference for transplanting male patients, especially from living donors, and we argue that this represents a cultural phenomenon within the Chinese population. The 10-yr graft survivals for related and cadaveric transplants are 86.2% and 67.4%, respectively. These figures are appreciably higher than corresponding figures in Caucasian populations. We show beneficial effects of using cyclosporin A, minimizing the cold ischemia time and avoiding very young and very old donors. There is a clear benefit of transplanting kidneys with zero or one mismatched HLA antigen against the recipient but no stepwise decrease in outcome as the number of mismatched antigens increases. There is close concordance between the outcome of living related grafts with zero, one, and two mismatched haplotypes against the recipient and no observable benefit of haplotype matching. We show that Chinese renal transplant recipients in other centers also have better long-term graft outcome than Caucasians, both for cadaveric and living related transplants. We draw attention to the existence of a detrimental "race effect" in other studies when Black recipients are compared with Caucasians and consider whether an enhancing race effect exists for Chinese or whether the better outcome reflects different underlying diseases in Chinese.

House dust mite allergens (Der p I and Der p V) within domestic environments of atopic and control children

We used allergen-specific ELISA to evaluate environmental distributions of house dust mite allergens (Der p I and Der p V) in the homes of 46 asthmatic, 20 atopic, and 26 nonatopic control children during the summer and winter. Geometric mean Der p I levels were approximately 10 times higher than geometric mean Der p V concentrations. The concentrations of Der p I and Der p V in winter were significantly higher than concentrations found in summer. In addition, we found no differences in Der p I concentrations among the three groups in summer; however, in winter, Der p I levels in the control group were significantly higher than levels in the homes of both asthmatic and atopic children. During the summer, concentrations of Der p V were lower in the control group, compared with the asthmatic group, but during the winter, concentrations in the control group were higher than levels found in either asthmatic or atopic children's homes. In this study, we did not establish an important relationship between mite allergen exposure and atopy/asthma.

Indoor pollution and sick building syndrome symptoms among workers in day-care centers

In this study, we investigated indoor air quality and symptoms of respiratory illness in 264 nursing workers at 28 day-care centers in Taipei. Geometric mean concentrations of indoor and outdoor bacteria were 735 colony-forming units in air (CFU/m3) and 384 CFU/m3, respectively. In addition, geometric mean concentrations of indoor and outdoor fungi were 1,212 CFU/m3 and 1,032 CFU/m3, respectively. Aspergillus, Cladosporium, and Penicillium-microfungi that occurred most commonly-were found indoors and outdoors. Geometric mean concentrations of house dust mite allergens, Der p I and Der p V, were 58 ng/g dust and 14 ng/g dust, respectively. In addition, the observed high prevalence of dampness or mold problems in the day-care centers indicated that dampness was very common in this subtropical region. We found a significant relationship between dampness and work-related sick building syndrome in the day-care-center workers. Furthermore, concentrations of fungi were lower in the day-care centers equipped with air conditioners/air cleaners than in centers that lacked such equipment. Also, Aspergillus was associated strongly with work-related sick building syndrome in the day-care-center workers.

Glutamate receptor antagonists block gustatory afferent input to the nucleus of the solitary tract

The effects of excitatory amino acid (EAA) receptor antagonists in blocking the synaptic transmission between gustatory fibers of the chorda tympani (CT) nerve and taste-responsive neurons within the nucleus of the solitary tract (NST) were examined electrophysiologically in urethan-anesthetized hamsters. Single neurons in the NST were recorded extracellularly and drugs were microinjected into the vicinity of the cell with the use of a multibarrel pipette assembly. The activity of each cell was recorded in response to lingual stimulation with 0.032 M NaCl, 0.032 M sucrose, 0.0032 M citric acid, 0.032 M quinine hydrochloride, and/or 25 microA anodal current pulses. Once a cell was identified as a taste-responsive neuron, one or more EAA receptor antagonists were administered by microinjection. Approximately 27 nl of 50 mM kynurenic acid (KYN), a broad-spectrum EAA receptor antagonist; 0.5 or 2.0 mM DL-2-amino-5-phosphonovalerate (APV), an N-methyl-D-aspartate (NMDA) receptor antagonist; 0.05 or 0.5 mM 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor antagonist; or phosphate-buffered physiological saline was applied to the neuron. Responses to chemical stimulation of the anterior tongue were obtained before and after drug administration and again after recovery; responses to anodal current stimulation (0.1 Hz) were obtained continually throughout the drug administration protocol. Microinjection of KYN completely and reversibly abolished responses elicited by both anodal current and chemical stimulation of the anterior tongue. The excitatory responses of cells in the NST to chemical and electrical stimulation of the anterior tongue were also completely and reversibly blocked by CNQX, implicating the involvement of an AMPA/kainate receptor. Microinjection of APV was generally less effective and partially reduced the responses of some taste-responsive NST cells to chemical stimulation of the anterior tongue. There were no effects following microinjection of a 27-nl bolus of phosphate-buffered saline. None of these EAA receptor antagonists had a differential effect on responses to different taste stimuli. The responses to all tastants were completely blocked by both KYN and CNQX; there was no apparent relationship between the response to any particular tastant and the limited effects of APV. These data implicate glutamate as an excitatory neurotransmitter between CT gustatory fibers and taste-responsive NST cells and suggest that it acts primarily on AMPA/kainate receptors, with some contribution from NMDA receptors. This conclusion is strengthened by other data obtained from in vitro slice preparations, which show that responses of cells in the rostral NST to solitary tract stimulation are blocked by both NMDA and AMPA/kainate receptor antagonists.

Airborne fungus allergen in association with residential characteristics in atopic and control children in a subtropical region

Airborne fungi were collected during the summer and winter seasons. A N6 Andersen sampler was used inside and outside the homes of 46 asthmatic children, 20 atopic children, and 26 nonatopic control children in the Taipei area. In addition, host and house characteristics were obtained by questionnaire. The indoor fungus concentrations of asthmatic and control groups were higher than those in atopic groups in summer, but there were no differences in total fungus concentrations among three groups in winter. Concentration differences among these three groups also occurred for Cladosporium and Penicillium in summer and for Aspergillus, Cladosporium, Penicillium, and yeast in the winter. Moreover, it was demonstrated that no differences in fungus concentration were observed between damp and dry homes. Penicillium concentrations appeared to be related to home dampness. Home dampness was associated with allergic symptoms in children with asthma and rhinitis. An association was also observed between the occurrence of Cladosporium and history of asthma.

Dampness and respiratory symptoms among workers in daycare centers in a subtropical climate

We evaluated the association between measures of dampness in daycare centers (N = 56) in the Taipei area and symptoms of respiratory illness in 612 employees. Dampness was found in 75.3% of the centers, visible mold in 25.8%, stuffy odor in 50.0%, water damage in 49.3%, and flooding in 57.2%. Furthermore, prevalence of sick building syndrome symptoms in the daycare workers was statistically significant among those who worked in centers that had mold or dampness. Also, the observed numerous incidences of dampness or mold in centers were very common in this subtropical region, and dampness was a strong predictor of sick building syndrome symptoms.

A partial dialysate collection method

This study validates Ing's partial dialysate collection method, which employs proportionate collection using a side tube capped with a small-gauge plastic needle. The urea nitrogen and creatinine levels of the small representative fraction of spent dialysate collected in the above fashion are undistinguishable from those obtained from the total spent dialysate. The estimated urea nitrogen removed during hemodialysis using this approach is similar to that using the total dialysate collection method; Ing's method is simple and useful in quantifying the dialysis dosage and in its assessment of the nutritional status of patients on hemodialysis.

Vomeronasal system involvement in response to conspecific odors in adult male opossums, Monodelphis domestica

The present study was designed to test the hypothesis that preferential nuzzling of unfamiliar conspecific odors by male opossums is vomeronasally mediated. Opossums were presented with vials containing their own odors (Own) and vials with odors from unfamiliar conspecifics (Novel) both before and after (Expt. 1) or only after (Expt. 2) vomeronasal nerve (VNNX) or sham (Sham) surgery. Nuzzling duration was greater for Novel before (Expt. 1) and after (Expts. 1 and 2) surgery both in VNNX and Sham animals, indicating that a functional vomeronasal system is not necessary for the differential nuzzling of novel odors. In contrast, differential scent marking of Novel was lost following VNNX, but not following sham surgery. Since VNNX lesions disrupt differential marking behavior but, not differential nuzzling, it is possible that different components of conspecific odors guide these two chemosensory behaviors and that these components may be detected by different sensory systems. Vomeronasal nerve lesions, confirmed histologically, resulted in the loss of the beta-NADPH-dependent reaction product from the accessory olfactory bulbs (AOB). The pattern of staining with 4 lectins, soybean agglutinin (SBA), Phosphocarpus tetragonolobus (PCT), Vicia villosa agglutinin (VVA), and Griffonia simplicifolia lectin I-isolectin B4 (GS I-B4) remained unchanged in the AOB following vomeronasal nerve lesions, although the size of the AOB appeared to decrease in the VNNX animals.

Home dampness and childhood respiratory symptoms in a subtropical climate

The association between measures of home dampness and symptoms of respiratory illness was evaluated in 1 340 8- to 12-y-old children in the Taipei area. The following were reported to occur in the homes: self-dampness (i.e., home considered damp by residents), 36.8% of the homes; "classified" dampness (i.e., presence of mold, water damage, or flooding), 72.3%; visible mold, 38.3%; stuffy odor, 33.9%; water damage, 47.8%; and flooding, 15.1%. Moreover, the prevalence of all respiratory symptoms was consistently higher in homes for which the occurrence of molds or dampness was reported. The adjusted odds ratios ranged from 1.37 (95% confidence interval: 1.03-1.83) for allergic rhinitis to 5.74 (95% confidence interval: 2.20-14.95) for cough. In addition, the observed high prevalence of home dampness/mold indicated that dampness in the home was very common in the subtropical region studied, and home dampness was a strong predictor of respiratory symptoms.