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Biomedical subjects

B Y Suh

Publications and source records attributed to B Y Suh.

14 recordsLinked to original sources
PubMed2001

Misinterpretation of sleep-breathing disorder by periodic limb movement disorder.

We report a case of misinterpretation of sleep-disordered breathing due to periodic limb movement disorder. A 67-year-old man was diagnosed with sleep-disordered breathing and subsequently placed on treatment with nasal continuous positive airway pressure (CPAP). The initial diagnostic evaluation did not include measurement of anterior tibialis electromyogram. The respiratory disturbance index of the initial evaluation was 23. After a brief period of nasal CPAP use, the patient discontinued the treatment because no significant change in daytime alertness was noted and signs of CPAP-related insomnia appeared. The patient was restudied polysomnographically with monitoring of anterior tibialis electromyograms. This study identified 392 leg movements of which 65% were associated with brief EEG arousal from sleep. Double-blind analysis of respiratory disturbance and leg movements yielded a total number of 360 arousals in the overnight recording. Eighty-five percent of all respiratory events could be associated with central hypoventilation following periodic limb movement-associated EEG arousal. No significant hypoxia was recorded with these events. We hypothesize that chemoreceptor stimulation secondary to EEG arousal during sleep is responsible for this central hypoventilation. This case report highlights that recording and scoring of leg movements must be an integral part of polysomnographic evaluations.

Aged↗
PubMed1996

Effects of non-REM sleep on ventilation and respiratory mechanics in adults with cystic fibrosis.

To determine the effects of sleep upon respiratory function, five adult patients with cystic fibrosis (CF) were monitored during sleep in a horizontal body plethysmograph. Tidal volume (VT) decreased during non-rapid-eye-movement (NREM) sleep, resulting in a NREM sleep-associated decrement in minute ventilation (VI = 11.10 +/- 0.67, 9.32 +/- 0.91, and 9.17 +/- 1.42 L during wakefulness, stage 2, and stages 3-4, respectively, p < 0.05). There were no NREM sleep-associated changes in respiratory frequency (f) or inspiratory time (Ti), but respiratory neuromuscular output was reduced during NREM sleep P0.1 = 3.33 +/- 0.57, 1.79 +/- 0.23, and 1.99 +/- 0.21 cm H2O during wakefulness, stage 2, and stages 3-4, respectively, p = 0.005). Upper airway resistance (Rua), lower airway resistance (RIa), and lung volume did not change in association with NREM sleep. Functional residual capacity (FRC) measurements made using helium dilution indicated large volumes of trapped gas, likely a result of peripheral airways that were closed at FRC. We conclude that in adult patients with CF, NREM sleep is associated with a decrement in VT and VI, NREM sleep does not alter airflow resistance or lung volume, and the observed reductions in VT and VI apparently result from a NREM sleep-associated decrease in respiratory neuromuscular output.

Adult↗
PubMed1995

Influence of sleep on respiratory function in emphysema.

To assess the influence of sleep on respiratory function, five patients with chronic obstructive pulmonary disease (COPD) with laboratory evidence of emphysema were monitored during sleep in a horizontal body plethysmograph. Neither lung volume nor lower airway resistance (Rla) changed in association with sleep. Upper airway resistance (Rua) increased during sleep and was highest during rapid eye movement (REM) sleep (Rua = 5.9 +/- 1.1, 9.6 +/- 2.1, 11.2 +/- 1.5, and 15.6 +/- 4.1 cm H2O/L/s during wakefulness, Stages 2, 3-4, and REM, respectively, p < 0.05). Tidal volume (VT) decreased during sleep, resulting in a sleep-associated decrement in minute ventilation (VI = 8.69 +/- 0.46, 7.64 +/- 0.65, 7.08 +/- 0.70, and 5.62 +/- 0.47 L during wakefulness, Stages 2, 3-4, and REM, respectively, p < 0.05). Respiratory neuromuscular output was also reduced during sleep (esophageal occlusion pressure [P0.1] = 2.69 +/- 0.39, 2.02 +/- 0.27, 1.90 +/- 0.27, and 1.63 +/- 0.25 cm H2O during wakefulness, Stages 2, 3-4, and REM, respectively, p = 0.005). We conclude that in patients with emphysema (1) sleep does not alter lung volume or increase lower airway resistance, (2) sleep is associated with a decrease in VT and VI, and (3) sleep is associated with an increase in Rua and a reduction in P0.1 that may contribute to the sleep-associated decrease in VI.

Adult↗
PubMed1995

Influence of sleep on pulmonary capillary volume in normal and asthmatic subjects.

To determine the effect of sleep upon intrapulmonary blood volume (as reflected by measurements of pulmonary capillary volume (VC), 5 normal subjects and 15 asthmatic patients were monitored overnight in our sleep laboratory. VC was determined before and after sleep from four measurements of DLCO using a single-breath technique, with subjects inspiring different oxygen concentrations for each measurement. Spirometry was performed in the supine posture before presleep VC measurements and immediately upon awakening before postsleep VC measurements. As defined by a > or = 15% overnight reduction in FEV1, 10 asthmatic subjects demonstrated nocturnal worsening. FEV1 decreased from 61.2 +/- 15.1 to 40.9 +/- 16.2% of predicted (p = 0.0001) in the 10 asthmatic patients with nocturnal worsening. Asthmatic patients with nocturnal worsening also demonstrated a 15.7 +/- 16.6% increase in VC from presleep to awakening (p = 0.02). Normal subjects and asthmatic patients without nocturnal worsening exhibited no significant overnight change in FEV1 or VC. We conclude that in asthmatic patients with nocturnal worsening sleep is likely associated with an increase in intrapulmonary blood volume.

Adult↗
PubMed1993

Altered luteinizing hormone pulse frequency in early follicular phase of the menstrual cycle with luteal phase defect patients in women.

OBJECTIVE: To delineate the relationship between the pulsatile gonadotropin inputs in early follicular phase of the menstrual cycle and the P secretions by the corpus luteum in women. DESIGN: For measuring pulsatile release of gonadotropin, blood samples were drawn every 15 minutes for 24 hours in the early follicular phase. Daily blood samples were drawn for LH, FSH, E2, and P. SETTING: The reproductive endocrine unit of a university hospital. PATIENTS: Fourteen patients with luteal phase defect (LPD) and 12 normally cycling women. RESULTS: The length of follicular phase in LPD was significantly shorter than that of women with normal cycles. There were significant differences in LH pulsatile secretions and amplitudes in LPD patients when compared with those of women with normal cycles. Basal E2, PRL, and preovulatory E2 concentrations were not different between the two groups whereas the peak of P secretions in luteal phase was significantly decreased in LPD. CONCLUSIONS: These data suggest that LPD may result from the altered LH pulse frequency in early follicular phase of the menstrual cycle. Whether this increased LH pulse frequency results from an intrinsic disease of the pulse oscillator or to some event in the preceding cycle remains unknown. It is tempting to speculate that an increased LH pulsatile secretion in the early follicular phase of menstrual cycles in patients with LPD may down-regulate the LH secretion at midcycle, thereby lowering the LH surge, which in turn reduces the P secretion in luteal phase.

Adult↗
PubMed1990

Relative changes in LH pulsatility during the menstrual cycle: using data from hypogonadal women as a reference point.

The basic premise of this study is that the GnRH-LH pulsatile activity, particularly its frequency characteristics, constitutes, in the absence of any considerable ovarian feedback, the intrinsic rhythm of the hypothalamic-pituitary unit at its maximal rate. Thus, LH pulse attributes determined in postpubertal hypogonadal subjects may be used as a reference in assessing the degree of influence exerted by endocrine factors that modulate GnRH-LH pulses. Accordingly, serum LH levels were determined in samples obtained at 15-min intervals for 24 h in 20 hypogonadal women: 13 postmenopausal women (PMW) and seven women with premature ovarian failure (POF). Similar measurements were performed in 60 normally cycling women: 25 in the early follicular phase (EFP), 13 in the late follicular phase (LFP), seven at midcycle surge (LH surge) and 15 in the midluteal phase (MLP). Significant pulses were identified by the cluster algorithm utilizing factors appropriate for 24 h data series of a sampling frequency of 15-min intervals. The results show a 24-h mean (+/- SE) LH pulse frequency of 78.2 +/- 2.8 and 85.5 +/- 2.4 min per pulse for young (POF) and older (PMW) hypogonadal women, respectively. During the follicular phase of the cycle, the LH pulse frequency is not significantly different from that of hypogonadal women, but there is a significant (P less than 0.05) increase from early to late follicular phases (95.4 +/- 3.3 vs 78.8 +/- 2.2 min per pulse). However, when the sleep periods are excluded from the 24-h data series because of the associated decrease of LH pulse frequency in EFP women, the resulting pulse frequencies are almost identical for EFP, LFP and PMW. An elevation beyond the basic pulse rhythm determined in PMW or POF is not observed in any phase of the menstrual cycle studied, including the midcycle surge. The decrease in LH pulse frequency during the luteal phase of the cycle (151.8 +/- 8.0 min per pulse, P less than 0.001 vs hypogonadal women) beyond the reference pulse frequency of hypogonadal women is unequivocal. By contrast, the pulse amplitude varies markedly among the groups with the largest found in POF (36.6 +/- 4.5 IU/l). It follows, in descending order, PMW (22.7 +/- 3.1 IU/l), midcycle surge (17.3 +/- 2.8 IU/l), MLP women (7.0 +/- 1.3 IU/l) and the EFP (4.9 +/- 0.3 IU/l) and LFP (4.0 +/- 0.4 IU/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Hypercortisolism in patients with functional hypothalamic-amenorrhea.

Hypercortisolism was found in patients with functional hypothalamic amenorrhea (HA) in preliminary short term studies conducted during the morning hours (0800-1100 h). This observation prompted us to characterize the circadian and pulsatile patterns of serum cortisol and LH levels at 15-min intervals for 24 h in 10 women with functional HA and in 7 normal women during the early follicular phase of their cycles. The mean integrated 24-h serum cortisol levels (area under the curve) were significantly (P less than 0.01) higher in the HA patients than in normal women. The mean cortisol levels in the HA patients were elevated (P less than 0.005) compared to those in the normal women during the daytime hours (0800-1600 h), but not during the evening (1600-2400 h) and sleeping hours (2400-0800 h). This selective hypercortisolism during the waking period of the day was almost entirely related to increased duration and amplitude of secretory episodes (peak area) rather than a change in pulse frequency. The serum cortisol increments in response to a noon meal that occurred in normal women were markedly impaired (P less than 0.01) in the HA patients. Compared with that in the normal women, mean LH pulse frequency was reduced by 30% in the HA patients. The 24-h mean LH levels and mean LH pulse amplitude were not significantly different from those in the normal women. However, among the HA patients there were marked individual differences in LH pulse frequency and amplitude, with prolonged interpulse quiescent periods, indicative of dysfunction of the hypothalamic GnRH pulse generator. We conclude that neuroendocrine activation of the ACTH-adrenal axis and inhibition of the GnRH pulse generator in women are associated with HA. Further, spontaneous resumption of normal cyclicity occurred in the majority (8 of 10) of the HA patients with no medical treatment, suggesting that this syndrome is a reversible hypothalamic disorder of a functional nature.

Adrenocortical Hyperfunction↗
PubMed1986

Role of oxytocin in the modulation of ACTH release in women.

To determine if oxytocin (OT) may have a modulatory role on corticotropin-releasing factor (CRF) and vasopressin (AVP) mediated ACTH-cortisol release in women, serial experiments were performed in which saline, OT, AVP and CRF were administered singly or in combinations. OT administration (2 IU intravenous bolus followed by 111 mIU/min infusion for 3 h) maintained a circulating concentration of 7.7 X 10(-8) M and did not significantly influence basal, AVP or CRF-induced ACTH-cortisol release. In contrast, OT inhibited significantly the potentiating effect of AVP on CRF-stimulated ACTH-cortisol release. These findings suggest that OT and AVP may modulate, in a reciprocal fashion, the CRF-mediated ACTH release and support the contention that OT may be involved in the neuroendocrine response to stress in women.

Adrenal Cortex↗
PubMed1985

Modulation of thymosin beta 4 by estrogen.

The endocrine thymus produces several hormone-like peptides (generically termed thymosins) which control development of the thymic-dependent lymphoid system and participate in the process of immune regulation. In addition, recent literature supports the hypothesis that gonadal steroids in general and estrogens in particular affect the immune system. To determine whether steroid hormones modulate secretion of thymic peptides, basal concentrations of thymosins alpha 1 and beta 4 were determined by radioimmunoassay in morning blood samples from 87 women in various clinical states. Basal concentrations of thymosin alpha 1 were similar in all women sampled. Basal levels of thymosin beta 4 were similar in normal women during the early follicular phase, women with premature ovarian failure, postmenopausal women not receiving estrogen, and individuals with gonadal dysgenesis. However, the marked variability of basal levels in premature ovarian failure and in postmenopausal women suggests that these groups are quite heterogeneous. Thymosin beta 4 concentrations were reduced in castrated women not receiving estrogen and were decreased more in both postmenopausal women and castrated women who were on chronic estrogen therapy. These data suggest that estrogens can modulate the circulating levels of thymosin beta 4 but not of thymosin alpha 1. We do not yet know whether sex steroids modulate secretion of other thymic peptides.

Adult↗
PubMedDate not supplied

Revision of hypo-osmotic swelling (HOS) test with a proposition of classified grading system: its comparisons with four different types of human sperm separation technique.

In this study, we arbitrarily classified the morphological changes of sperm under hypo-osmotic condition and compared the results with four different sperm separation techniques. The morphology of classification ranged from a good swelling (SG 3 > SG 2 > SG 1), to non-swelling but reactive (SG 0-R), and completely non-swelling (SG 0). Thirty fresh semen from patients were divided into 4 groups and each processed by washing, swim up, 2-layer column and real time micro-separation system. The prevalent patterns of the swollen sperm in sequence after treatment was SG 0 > SG 1 > SG 3 > SG2 > SG 0-R in fresh semen, and the proportion of SG 0 was almost half of the total % HOS test results. However, SG 3 became the most common swollen form with a significant increase in number with any method of sperm preparation after treatment. The real time technique yielded the highest % rate of SG 3 type of swollen spermatozoa and was the richest in concentration (53+/-3.9%, P < 0.05) as compared with that of swim up (26+/-4.6%), 2-layer (20+/-4.4%), sperm washing (23+/-3.9%), and fresh semen (17+/- 2.8%), respectively. By contrast, 2-layer collected more number of SG0-R (5.3+/-1.2%, P < 0.05) pattern of spermatozoa when compared to real time and swim up. A positive correlation (r = 0.81, P < 0.002) was shown between the % total HOS spermatozoa and total motility of fresh semen but not with morphology. Collectively, an abnormally functional sperm may exist in almost half of a total sperm count from men. It would appear that a better potential fertilization capacity may reside in the more swollen sperm from HOS test than the less swollen sperm and that may be more related with the motility rather than the morphology. The HOS classification and grading system appears valuable in further evaluating sperm quality.

Cell Culture Techniques↗