Addressing Gender Disparity: Increase in Female Leadership Increases Gender Equality in Program Director and Fellow Ranks

INTRODUCTION

Women make up 15% of the total number of practicing gastroenterology (GI) physicians in the US. Despite this disparity, only 33% of the current GI fellows are female. Increasing female GIs is a major goal of all four GI societies. It is known that gender disparity exists in the field of gastroenterology, and women are underrepresented in the leadership ranks and trainee level at academic programs. Whether an increase in female leadership in academic medicine is associated with an increase in female program directors and trainees is unknown. The aim of this study was to assess this relationship in GI.

MATERIALS AND METHODS

Data were collected via a standardized protocol from all 173 US gastroenterology fellowship programs up until October 2018 from program websites and supplemented by online surveys completed by program coordinators. Any missing information was collected by calling the program coordinators. Data were collected on gender and academic rank of the program director, associate program director, division chief, chair of medicine, program size, academic center affiliation, number, and academic rank of female faculty and geographic region. The association was assessed using a Chi-square test or independent samples t test.

RESULTS

In leadership positions, men were listed as comprising 86% of chairs, 82% of division chiefs, 76% of program directors and 63% of associate program directors. Forty-three percent of programs did not have female representation at any leadership level. The presence of a female program director or female associate program director was associated with an increase in the number of female fellows (4.03 vs 3.20; p = 0.076; 4.26 vs 3.36; p = 0.041), respectively. Overall, the presence of a female in any leadership position led to an increase in the number of female fellows (4.04 females vs 2.87 females; p = 0.007) enrolled in a program. If a GI division chief was male, the program director was more likely to be male as well (81% male vs. 18.8% female). Conversely, having a female division chief was likely to lead to a more equitable program director representation, 54% female to 48% male (p value < 0.0001, OR 5.03 95% CI 2.04-12.3). Furthermore, if either the internal medicine department chair or GI chief was female, the proportion of female program directors increased to 41% as compared to 19% if both were male (p value < 0.0001, OR 2.99 95% CI 1.34-6.6).

CONCLUSION

Women are significantly underrepresented in the number of practicing gastroenterologists, at all levels of leadership in GI fellowship programs, and at the fellow level. Increasing the number of women in fellowship leadership positions is associated with an increase in female program directors and trainees. Per our knowledge, this is the first study to examine the relationship between female leadership in fellowship programs and the gender of trainees. Increasing female representation in leadership positions would not only address current gender disparity, but it may also increase the number of female future GI trainees.

Sympathetic predominance before tourniquet deflation is associated with a reduction in arterial blood pressure after tourniquet deflation during total knee arthroplasty

High dependency of arterial blood pressure (ABP) on enhanced sympathetic activity, which maintains vascular tone, leads to hypotension after hemodynamic insults that blunt the sympathetic activity. Therefore, we hypothesized that sympathovagal balance before tourniquet deflation (TD) determines the extent of a reduction in ABP after TD during total knee arthroplasty (TKA). Fifty-four hypertensive female patients undergoing TKA under spinal anesthesia were analyzed. The sympathovagal balance [low-to-high frequency ratio of heart rate variability (LF/HF)] before TD was defined as (LF/HF during 5 min before TD-preanesthetic LF/HF)/preanesthetic LF/HF (%). An increase in its value represents a shift in sympathovagal balance toward sympathetic predominance. The percent change in the mean ABP (MAP) after TD was defined as (minimum MAP during 10 min after TD-averaged MAP during 5 min before TD)/averaged MAP during 5 min before TD (%). Simple linear regression was performed to assess the correlation between the sympathovagal balance before TD and change in MAP after TD. The correlation was also assessed by multiple linear regression controlling for age, duration of tourniquet inflation, and spinal anesthesia-induced hypotension. Thirty-two minutes (on average) after tourniquet inflation, the MAP was decreased by 12.1 (-3.0 to 47.9) % [mean (range)] upon TD (P<0.001). The sympathovagal balance before TD was negatively proportional to the change in MAP after TD in both simple and multiple linear regression models (R2=0.323 and 0.340, P<0.001). A shift in sympathovagal balance toward sympathetic predominance before TD is associated with a decrease in ABP after TD.

Wireless 24, 48, and 96 Hour or Impedance or Oropharyngeal Prolonged pH Monitoring: Which Test, When, and Why for GERD?

PURPOSE OF REVIEW

pH monitoring technologies are routinely utilized in practice to further evaluate symptoms of gastro-esophageal reflux disease and laryngopharyngeal reflux (LPR). This is a review of the recent literature of the available pH monitoring technology and creates an algorithm in the diagnostic work up of a patient with GERD or LPR.

RECENT FINDINGS

The catheter-free wireless pH monitor traditionally collects data for 48 h. Recent studies have found that extending to 96 h can be helpful in patients with conflicting results on the first 2 days of the study. In addition, 96 h can allow for testing both on and off of PPI therapy. The oropharyngeal monitoring device is a newer technology that is designed to aid in the diagnoses of LPR. There are limitations with this technology as there is no universal abnormal cutoff and some studies have suggested a poor correlation between multichannel intraluminal impedance-pH (MII-pH) and the oropharyngeal monitoring device. MII-pH has recently developed two additional parameters, the measurement of three 10-min nighttime periods and the post-reflux swallow-induced peristaltic wave (PSPW) index, both of which may increase accuracy of testing. Each of these technologies can provide unique data regarding acid reflux exposure in the esophagus and oropharynx. The wireless pH monitor performed off of PPI therapy can help to establish or exclude the diagnosis of GERD. For those patients with refractory symptoms on PPI, MII-pH study can be performed while on therapy and provides data regarding the response to treatment. Oropharyngeal pH monitoring is being utilized in some practices to aid in diagnosis of LPR, but the scientific validity is controversial.

Neutrophil-lymphocyte ratio predicts response to chemotherapy in triple-negative breast cancer

Background

The neutrophil-lymphocyte ratio (nlr) has been reported to correlate with patient outcome in several cancers, including breast cancer. We evaluated whether the nlr can be a predictive factor for pathologic complete response (pcr) after neoadjuvant chemotherapy (nac) in patients with triple-negative breast cancer (tnbc).

Methods

We analyzed the correlation between response to nac and various factors, including the nlr, in 87 patients with tnbc who underwent nac. In addition, we analyzed the association between the nlr and recurrence-free survival (rfs) in patients with tnbc.

Results

Of the 87 patients, 25 (28.7%) achieved a pcr. A high Ki-67 index and a low nlr were significantly associated with pcr. The pcr rate was higher in patients having a high Ki-67 index (≥15%) than in those having a low Ki-67 index (35.7% vs. 0%, p = 0.002) and higher in patients having a low nlr (≤1.7) than in those having a high nlr (42.1% vs. 18.4%, p = 0.018). In multiple logistic analysis, a low nlr remained the only predictive factor for pcr (odds ratio: 4.274; p = 0.008). In the survival analysis, the rfs was significantly higher in the low nlr group than in the high nlr group (5-year rfs rate: 83.7% vs. 66.9%; log-rank p = 0.016).

Conclusions

Our findings that the nlr is a predictor of pcr to nac and also a prognosticator of recurrence suggest an association between response to chemotherapy and inflammation in patients with tnbc. The pretreatment nlr can be a useful predictive and prognostic marker in patients with tnbc scheduled for nac.

Association between basal-like phenotype and BRCA1/2 germline mutations in Korean breast cancer patients

INTRODUCTION

BRCA mutation testing allows index patients and their families to be provided with appropriate cancer risk-reduction strategies. Because of the low prevalence of BRCA mutations in unselected breast cancer patients and the high cost of genetic testing, it is important to identify the subset of women who are likely to carry BRCA mutations. In the present study, we examined the association between BRCA1/2 germline mutations and the immunohistochemical features of breast cancer.

METHODS

In a retrospective review of 498 breast cancer patients who had undergone BRCA testing at Seoul National University Bundang Hospital between July 2003 and September 2012, we gathered immunohistochemical information on estrogen receptor (er), progesterone receptor (pr), her2 (human epidermal growth factor receptor 2), cytokeratin 5/6, egfr (epidermal growth factor receptor), and p53 status.

RESULTS

Among the 411 patients eligible for the study, 50 (12.2%) had germline mutations in BRCA1 or BRCA2. Of the 93 patients with triple-negative breast cancer (tnbc), 25 with BRCA1/2 mutations were identified (BRCA1, 20.4%; BRCA2, 6.5%). On univariate analysis, er, pr, cytokeratin 5/6, egfr, and tnbc were found to be related to BRCA1 mutations, but on multivariate analysis, only tnbc was significantly associated with BRCA1 mutations. Among patients with early-onset breast cancer or with a family history of breast or ovarian cancer, BRCA1 mutations were significantly more prevalent in the tnbc group than in the non-tnbc group.

CONCLUSIONS

In the present study, tnbc was the only independent predictor of BRCA1 mutation in patients at high risk of hereditary breast and ovarian cancers. Other histologic features of basal-like breast cancer did not improve the estimate of BRCA1 mutation risk.

Characteristic of InGaN/GaN Laser Diode Grown by a Multi-Wafer MOCVD System

InGaN/GaN multi-quantum well (MQW) laser diodes (LDs) were grown on c-plane sapphire substrates using a multi-wafer MOCVD system. The threshold current for pulsed lasing was 1.6 A for a gain-guided laser diode with a stripe of 10 × 800 μm2. The threshold current density was 20.3 kA cm−2 and the threshold voltage was 16.5 V. The optical power ratio of transverse electric mode to transverse magnetic mode was found to be greater than 50. The characteristic temperature measured from the plot of threshold current versus measurement temperature was between 130 and 150K.

Effects of a modified live CSFV vaccine on the development of PMWS in pigs infected experimentally with PCV-2

The objective of this study was to determine the effect of vaccination against classical swine fever virus (CSFV) on the development of postweaning multisystemic wasting syndrome (PMWS) in conventional pigs infected experimentally with porcine circovirus type 2 (PCV-2). The pigs infected with PCV-2 and immunised with modified live CSFV developed mild to moderate PMWS, whereas none of the pigs infected with PCV-2 alone or immunised with modified live CSFV alone developed PMWS. Lesions histologically characteristic of PMWS were observed in lymph nodes from the pigs infected with PCV-2 and immunised with modified live CSFV vaccine, and extensive replication of PCV-2 was detected in the nodes by in situ hybridisation.

Efficient taste and odour removal by water treatment plants around the Han River water supply system

Seven major water treatment plants in Seoul Metropolitan Area, which are under Korea Water Resources Corporation (KOWACO)'s management, take water from the Paldang Reservoir in the Han River System for drinking water supply. There are taste and odour (T&O) problems in the finished water because the conventional treatment processes do not efficiently remove the T&O compounds. This study evaluated T&O removal by ozonation, granular activated carbon (GAC) treatment, powder activated carbon (PAC) and an advanced oxidation process in a pilot-scale treatment plant and bench-scale laboratory experiments. During T&O episodes, PAC alone was not adequate, but as a pretreatment together with GAC it could be a useful option. The optimal range of ozone dose was 1 to 2 mg/L at a contact time of 10 min. However, with ozone alone it was difficult to meet the T&O target of 3 TON and 15 ng/L of MIB or geosmin. The GAC adsorption capacity for DOC in the three GAC systems (F/A, GAC and O3 + GAC) at an EBCT of 14 min is mostly exhausted after 9 months. However, substantial TON removal continued for more than 2 years (>90,000 bed volumes). GAC was found to be effective for T&O control and the main removal mechanisms were adsorption capacity and biodegradation.

Variations in the behaviors to novel objects among five inbred strains of mice

Novelty stimuli cause various behavioral responses, such as exploration and avoidance, and contextual variables may contribute to the behavioral outputs. Here, we tried to compare the behavioral responses to novel objects of five inbred strains of mice (C57BL/6J, 129/svJae, C3H/HeJ, BALB/cJ and DBA/2J) by using a modified novel object test where a small light-weight cube wrapped with paper was presented to mice in a home cage without beddings. In response to these objects, the C57BL/6J, 129/svJae and C3H/HeJ mice showed mild exploratory behaviors, such as approaching, sniffing or brief contact. In striking contrast, the BALB/cJ and DBA/2J mice, which have been known to show high avoidance/low exploration in other behavioral paradigms, exhibited play-like secondary reactions toward the objects after initial primary exploratory behaviors. Specifically, DBA/2J mice would move the object around in the cage, holding it with their mouths, and BALB/cJ mice would gnaw the object, eventually stripping off the wrapping paper. Such behaviors decreased when similar objects were presented repeatedly. The present results suggest that active manipulations of novel objects may be a relevant parameter for measuring novelty-induced behaviors in mice and appear to be strongly influenced by genetic factors.

Blockade of p38 mitogen-activated protein kinase pathway inhibits interleukin-6 release and expression in primary neonatal cardiomyocytes

The induction of interleukin-6 (IL-6) using combined proinflammatory agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) was studied in relation to p38 mitogen-activated protein kinase (MAPK) and NF-kappaB transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, IFN-gamma enhancement of TNF-alpha-induced NF-kappaB binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on TNF-alpha/IFN-gamma or LPS/IFN-gamma-induced NF-kappaB activation. This study strongly suggests that these pathways about TNF-alpha/IFN-gamma or LPS/IFN-gamma-activated IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

Pyrrolidine dithiocarbamate inhibits serum-induced NF-κB activation and induces apoptosis in ROS 17/2.8 osteoblasts

Nuclear factor-kappaB (NF-kappaB) activity affects cell survival in ROS 17/2.8 osteoblasts. Preventing NF-kappaB transcription activity with a potent NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC), results in apoptosis. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor-kappaB (NF-kappaB) in serum-exposed condition, on the activation of mitogen activated protein kinase (MAPK), especially, JNK/SAPK and p38 MAPK induction. PDTC transiently increased the phosphotransferase activity of c-Jun N-terminal Kinase1 (JNK1), which might in turn activates transcriptional activity of activating protein-1 (AP-1). The activation of JNK was completely decreased in dominant negative JNK1 transfected cells and the PDTC-induced cell death was attenuated in these cells. In addition, AP-1 activation was decreased in the JNK1 transfected cells, compared with vector-transfected cells. The NF-kappaB inhibitor also transiently activates p38 MAPK but SB203580, a specific p38 MAPK inhibitor, does not have any regulatory effect on PDTC-induced cell death, suggesting that the cell death is mediated by JNK not by p38 MAPK. Thus, overall, these results show that PDTC induces apoptosis and suggest that JNK/SAPK and subsequent AP-1 activation may be involved in the apoptotic pathway in ROS 17/2.8 osteoblasts.

Suppression of the growth/differentiation transition in Dictyostelium development by transient expression of a novel gene, dia1

In Dictyostelium discoideum Ax-2 cells, a specific checkpoint (PS point) from which cells enter the differentiation phase in response to starvation has been specified in the cell cycle. Using the differential display method, we isolated a novel gene, dia1 (differentiation-associated gene 1), that is specifically expressed in cells differentiating from the PS point. The dia1 mRNA has an open reading frame of 1,368 bp and is deduced to code for a 48.6 kDa protein (DIA1). The DIA1 protein is highly serine-rich and the serine residues are predominantly located in the C-terminal region. After the PSORT II search, the protein is predicted to be GPI-anchored at the plasma membrane. Unexpectedly, dia1 overexpression rather impaired the progression of differentiation, possibly coupled with the reduced expression of early genes such as cAMP receptor1 (car1). The inhibitory effect of dia1 expression on early differentiation was almost completely nullified by externally applied cAMP pulses. In contrast to dia1 overexpression, antisense RNA-mediated dia1 inactivation was found to enhance the initial step of cell differentiation, as exemplified by precocious expression of car1 and other early genes. We discuss the unique structure and function of DIA1 in relation to the cooperative development of cells during the establishment of multicellular organization.

An antigen reacting with das-1 monoclonal antibody is ontogenically regulated in diverse organs including liver and indicates sharing of developmental mechanisms among cell lineages

The monoclonal antibody designated mAb Das-1, which was generated against a colon epithelial protein, reacts with the normal biliary epithelium and keratinocytes, which are among targets of tissue injury in ulcerative colitis. Moreover, mAb Das-1 reacts with abnormal cells in Barrett's esophagus and chronic cystitis profunda, as well as so-called 'oval cells' in the adult liver, which are considered oncogenic progenitor cells. To establish ontogenic regulation of mAb Das-1 reactivity, we studied 7- to 24-week-old human fetuses by immunohistochemistry. In liver, mAb Das-1 reactivity was further correlated with glycogen, dipeptidyl peptidase IV, glucose-6-phosphatase and gamma-glutamyl transpeptidase expression. mAb Das-1 reacted with cells in organs arising from the pharyngeal cleft (thymus), primitive gut (oral cavity, pharynx, lung, esophagus, stomach, biliary tree, pancreas, liver, colon), ureteric bud (renal tubules, collecting duct), mesonephros (kidney, testis), mesoderm (muscle) and elsewhere (skin, adrenal cortex). In distinction from the adult liver, mAb Das-1 staining was more pronounced in hepatoblasts compared with biliary cells. In adult tissues, however, mAb Das-1 reactivity was restricted to the colon, biliary epithelium, keratinocytes, and ciliary body. These data indicated that the mAb Das-1 recognized epitopes in fetal cells of diverse ectodermal, mesodermal and endodermal origin, compatible with sharing of lineage mechanisms in tissues. Reactivation of mAb Das-1 staining in epithelial precancerous conditions, including carcinomas arising in these organs, is compatible with oncofetal regulation of the antigen, which will facilitate analysis of cell subpopulations during organ development, regeneration and oncogenesis.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Expressed sequence tags of radish flower buds and characterization of a CONSTANS LIKE 1 gene

Expressed sequence tag (EST) analysis was conducted for young flower buds of radish plants. Among a total of 66 ESTs examined, 40 showed a significant similarity to previously identified genes. Twenty-eight ESTs were similar to proteins identified in other plants, 11 were similar to eukaryotic proteins other than plants, and one was similar to a prokaryotic protein. Four clones were selected for further studies. EST clone 81, which showed a homology to germin-like proteins was expressed more abundantly in leaves and roots as compared to flower buds. Clone 105 was highly homologous to the translation inhibitor protein and was expressed in all three organs, but the expression level was higher in flower buds and roots. Another EST clone, 133, which shared a significant similarity with the Ran-binding protein, hybridized to two different size transcripts that were detectable only in flower buds. Clone 39 was a homolog of CONSTANS, which is a gene involved in controlling the flowering time in Arabidopsis. The cDNA clone of EST clone 39 containing the entire open reading frame was obtained and designated as RsCOL1 (Raphanus sativus CONSTANS LIKE 1). It was 1049 bp long and contained an open reading frame of 307 amino acid residues (calculated molecular mass = 33.1 kDa). The RsCOL1 protein contained two putative zinc finger motifs in the amino terminal region which were 59% identical to the corresponding region of the Arabidopsis CO protein. The radish protein also contained a predicted nuclear localization domain in the carboxyl terminal region which was 87% identical to the corresponding region of CO. DNA blot analysis revealed that the radish genome contained several genes similar to RsCOL1. RNA blot analysis showed that RsCOL1 was strongly expressed in flower buds at the early bolting stage, and the expression level declined as the flower bud matured. The transcript was also detectable in leaves and roots. In mature flowers, the RsCOL1 transcript was present primarily in carpels.

Controlling the judge variable in grading essay-type items: an application of Rasch analyses to the recruitment exam for Korean public school teachers

The purpose of this paper is to show how the Rasch measurement model can be used to control the effects of judge variable on the grading of essay-type items in the recruitment test for Korean teachers. Special attention is given to two aspects of judges' involvement in the grading. One is to identify a way to minimize the variation of grading due to judge severity. The other concern is to figure out a way to reduce the number of judges without threatening objectivity of ability estimates. Results from the FACETS analyses tell us not only how much grading standards vary among judges and how to adjust them but also it produces comparably reliable ability estimates with fewer judges.

Cloning and sequence analysis of the cDNA encoding the elongation factor-1 beta of Dictyostelium discoideum

A cDNA encoding elongation factor-1 beta (DdEF-1 beta) for protein synthesis was isolated from Dictyostlium discoideum cells by the differential display (DD) method. The DdEF-1 beta cDNA sequence with a length of 733 bp encodes a protein (M(r) 24.1 kDa) consisting of 214 amino acids. Comparison of the predicted amino acid sequence revealed relatively high homology to that of DdEF-1 beta from silkworm (59%), human (57%) and Xenopus (55%). Northern analysis showed that the DdEF-1 beta mRNA is maximally expressed during the vegetative growth phase, followed by marked decrease in response to cell differentiation induced by starvation.

Uvula-nodulus and gravity direction (a study on vertical optokinetic-oculomotor functions)

Some characteristics of vertical optokinetic nystagmus and after-nystagmus, in particular, its up/down gain asymmetry, are known to be influenced by gravity direction, which is basically perceived by otolith organs. However, how such an information of gravity direction is processed within the central nervous system is not well understood, even though the role of cerebellar uvula and nodulus in vertical eye movements has been identified for some time. Accordingly, in this study, vertical optokinetic nystagmus and after-nystagmus were studied in squirrel monkeys both in the upright and side-lateral positions (different gravity direction to the head), before and after uvulonodulectomy. When the optokinetic stimulus was given, the slow phase eye velocity of optokinetic nystagmus was significantly higher in the side-lateral position than that obtained in the upright position. This difference disappeared after uvulonodulectomy. When the initial slow phase eye velocity of optokinetic after-nystagmus was compared, the one obtained in the side-lateral position was significantly higher than that acquired in the upright position. This difference also disappeared after the uvulonodular ablation. Thus, in this study of vertical optokinetic nystagmus and after-nystagmus, the role of uvula and nodulus in relaying the information of gravity direction was confirmed.

Lymphoid development in mice congenitally lacking T cell receptor alpha beta-expressing cells

Vertebrate T cells express either an alpha beta or gamma delta T cell receptor (TCR). The developmental relatedness of the two cell types is unresolved. alpha beta + T cells respond to specific pathogens by collaborating with immunoglobulin-producing B cells in distinct lymphoid organs such as the spleen and Peyer's patches. The precise influence of alpha beta + T cells on B cell development is poorly understood. To investigate the developmental effects of alpha beta + T cells on B cells and gamma delta + T cells, mice homozygous for a disrupted TCR alpha gene were generated. The homozygotes showed elimination of alpha beta + T cells and the loss of thymic medullae. Despite this, gamma delta + T cells developed in normal numbers, and there was an increase in splenic B cells.

Compensation of vertical vestibulo-ocular functions in squirrel monkeys after unilateral labyrinthectomy

Modifications in the vertical vestibulo-ocular reflex (VVOR) were studied in four squirrel monkeys (Saimiri sciureus) over time after unilateral labyrinthectomy. In the dark, with head upright, animals were exposed to sinusoidal rotation in the pitch plane. The magnetic field-pericorneal search coli technique was used to detect eye movement. The upward and downward slow-phase eye velocity (SPEV) of the VVOR and the maximum SPEV of the vertical component of spontaneous nystagmus (SPN) were studied. The mean preoperative gain of VVOR was symmetric. After unilateral labyrinthectomy, the maximum reduction of VVOR gain showed an asymmetry. The recovery of VVOR gain to the preoperative level took about 2 weeks, and the vertical component of SPN was present for about 3 weeks.

Autonomic indexes during the vestibular-visual conflict exposure: a squirrel monkey study

To assess the dynamic changes of the autonomic neural responses evoked by vestibular-visual conflict (VVC) in the squirrel monkey, we analyzed the changes of salivary amount and sodium concentration, and the coefficient of variance (CV) of R-R intervals (RRI) along the time course of VVC exposure given in pitch plane. The sodium concentration and the amount of saliva showed clear increases at the first and second 15 min stimulation periods. The CV of RRI was found to increase over the entire periods of stimulation, and there was a significant difference between the rest value and those in stimulated periods. The correlation between the CV of RRI, and amount of salivation was highly positive. These results indicate the existence of a common pattern of autonomic neural response during VVC, and suggest usefulness of these indexes for objectively monitoring the severity of motion sickness.

Second-phase optokinetic after-nystagmus and vestibular compensation

To evaluate the direction-specific effect of optokinetic storage function on balance compensation after unilateral labyrinthectomy, squirrel monkeys (n = 12) were exposed to a prolonged (30 min) daily optokinetic stimulus (horizontal, constant speed-90 degrees/sec) for 14 days; either in the ipsilateral direction to the slow phase of spontaneous nystagmus, or in the contralateral direction, or without any optokinetic stimulus. The effect of optokinetic stimulus in ipsilateral direction (slow phase of OKAN-II in the opposite direction) was significantly more (p less than 0.001) in the vestibulo-oculomotor balance (static) regainment than the other two groups, but this group showed the severest gait deviation in the vestibulospinal balance function (p less than 0.05).

Insulin patterns in equivocal glucose tolerance tests (chemical diabetes)

Hyperinsulinemic patterns are a well recognized feature of equivocal glucose tolerances of the chemical diabetes type, i.e. those that are neither definitely nondiabetic nor clearly diabetic. A more complete characterization of such insulin responses is obtained when the data are expressed in terms of increments in insulin from the zero time point.

Thus, two patterns of insulin increments after oral glucose become evident when the equivocal zone of glucose tolerance is divided into lower and upper segments. Tests in the lower segment show normal increments at the halfhour point of the test; at one hour these tests show excessive increments which persist throughout the five hours of observation. On the other hand, tests in the upper zone show delays in the serum insulin rise at the half-hour point, followed by normal increments at one hour and excessive increments thereafter. The pattern is the same whether or not obesity is present.

It is suggested that tests in the equivocal zone of Glucose Tolerance Sum values be taken to be indicative of chemical diabetes. Tests with the Sum in the lower half of the equivocal zone could then represent chemical diabetes with mild intolerance stemming from insulin ineffectiveness, since insulin increments in this group are at or above the mean values recorded in nondiabetic controls. On the other hand, chemical diabetes with moderate glucose intolerance and Glucose Tolerance Sums in the upper half of the equivocal zone would be understood to result from a combination of an initial delay in the serum insulin rise followed by normal and then excessive increments in serum insulin with the latter two indicative of insulin ineffectiveness. However, insulin ineffectiveness may also be present at the time of the insulin delay.

High glucose:insulin ratios in tests indicative of chemical diabetes are almost always attributable to higher glucose increments with insulin increments normal or excessive compared to normal glucose tolerances. Deficient insulin increments contribute to the high ratios only at the half-hour point in tests with Glucose Tolerance Sums in the upper zone of equivocal glucose tolerances.