Correlation of progesterone levels on the day of oocyte retrieval with basal hormonal status and the outcome of ART.

This study aimed to assess whether basal hormonal levels can predict the levels of progesterone (P4) on the day of oocyte retrieval (OR) and examine the impact of P4 levels on the day of OR on the outcome of assisted reproduction. One hundred sixty-four patients that were enrolled in the assisted reproduction procedure were classified according to their P4 levels on the OR day (< 2 ng/ml vs. ≥ 2 ng/ml). Patients who had P4 levels < 2 ng/ml had significantly higher follicle stimulating hormone (FSH) levels and significantly lower anti-Mullerian hormone (AMH) levels. More than half of patients with P4 levels < 2 ng/ml on the OR day got pregnant and delivered healthy infants. There was a significant correlation between lower FSH values and higher P4 values at OR and between higher AMH values and higher P4 values on the day of OR. Regression analysis showed that high FSH levels are the most important factor that can reliably imply lower P4 levels on OR day. Our study confirmed that lower basal FSH levels can predict the levels of P4 on the OR day. Moreover, lower levels of P4 on the day of OR are associated with a positive outcome in assisted reproduction.

Distinctive pattern of c-fos expression in the feline cervico-lumbar spinal cord after stimulation of vanilloid receptors in dorsal neck muscles.

In the present study, c-fos expression in the spinal cord has been used as a marker of neuronal activation induced by capsaicin-sensitive sensory afferents from the dorsal neck muscles in cats (n = 6). The number of Fos-immunoreactive neurons, which were revealed using the avidin-biotin-peroxidase method, was significantly increased in the cervical and lumbar spinal cord. In contrast to the control group (n = 3), 2 h after intramuscular capsaicin injection, c-fos expression was more extensive ipsilaterally to the injected side in the C3-C6 segments, and bilaterally in the L4-L6 segments. Most labeled neurons in the cervical spinal cord were small and giant cells, predominantly located in the middle and lateral parts of lamina I and, additionally, at the neck of the dorsal horn (lamina V), i.e., within the zones of termination of high-threshold muscle afferents. The widespread distribution of labeled cells throughout the cervical cord within the intermediate zone (lamina VII) coincided with the sites of last-order premotor interneurons and cells of origin of long crossed and uncrossed descending propriospinal pathways to the lumbar spinal cord. These findings suggest possible mechanisms for spreading of nociceptive signals between cervical and lumbar regions.

Spreading of fatigue-related effects from active to inactive parts in the medial gastrocnemius muscle of the cat.

In the medial gastrocnemius muscle of the decerebrate cat, the spatial spread of fatigue between active and inactive muscle parts was studied. Conditioning fatiguing stimulation (CFS) was applied to a part of the muscle to test whether it had an effect on the contraction efficiency in an unstimulated part. To exclude somato-sympathetic reflexes during CFS, a full rhizotomy of the lumbo-sacral spinal cord was performed. The same ipsilateral ventral root, either L7 or S1, was divided into seven filaments, one of which was used for the test stimulation, and four or five for CFS. The CFS consisted of 12 s sessions of distributed stimulation of five (or four) filaments at a rate of 40 s(-1), the sessions were repeated, every 40 s, 15 or more times. The test consisted of 12 s of regular stimulation at a rate of 10 s(-1), preceded and followed by a single stimulus. The tests applied just after CFS showed a strong decline of both tension and electromyogram (EMG), amounting to only [mean (SD)] 0.45 (0.18) and 0.51 (0.19) (n = 15), respectively, of the corresponding values in the tests before CFS. It thus turned out that depressive fatigue-related effects could spread within the muscle. At the same time, control reactions recorded in the lateral gastrocnemius during stimulation of its cut nerve did not change. Subsequent repetitions of the tests usually revealed a tendency towards restoration. The EMG reactions recovered more quickly than tension. The depression of EMG after CFS was accompanied by a slowing of the constituent M-waves; their latencies decreased during restoration. Distinct changes in the systemic blood pressure were observed during CFS. These changes were usually correlated well with muscle tension changes. The factors possibly underlying the observed effects may include diffusion of metabolites from active to inactive muscle fibres, lowering of the efficiency of neuro-muscular transmission due to squeezing of efferent motor terminals and changes in outer metabolite content, as well as local hypoxia due to increases in intramuscular pressure.

c-fos Expression and NADPH-d reactivity in spinal neurons after fatiguing stimulation of hindlimb muscles in the rat.

The distribution of Fos-immunoreactive (Fos-ir) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-reactive neurons in the rat lumbar spinal cord was examined following muscle fatigue caused by intermittent high-rate (100 s(-1)) electrical stimulation of the triceps surae muscle or the ventral root L5 (VRL5) for 30 min. Following both types of stimulation, the fatigue-related c-fos gene expression was more extensive in the L2-L5 segments on the stimulated side, and the majority of Fos-ir neurons were concentrated in the dorsal horn. After direct muscle stimulation, the highest number of Fos-ir neurons were detected in two regions: layer 5, and superficial layers (1 and 2(o)), although many labeled cells were also found in layers 3, 4, 6, and 7. In response to VRL5 stimulation, the maximal density of Fos-ir neurons was detected in the middle and lateral parts of layers 1 and 2(o), the zone of termination of high-threshold muscle afferents(.) Statistically significant prevalence of Fos-ir cell number was also found in layers 5 and 7 on the stimulated side. A few Fos-ir neurons were detected in the ventral horn (layer 8 and area 10) on both sides. The lamellar distribution of NADPH-d-reactive neurons was similar over all experimental groups of animals. In the L3-L6 segments, such reactive cells were arranged in two distinct regions: dorsal horn (layers 2(i), 3, and 5) and area 10; in the L1 and L2 segments, an additional cluster of NADPH-d positive cells was found in the intermediolateral cell column (IML). Double-labeled cells were not detected. We suggest that c-fos expression in response to muscle fatigue reveals activity of functionally different types of spinal neurons which could operate together with NOS-containing cells in pre-motoneuronal networks to modulate the motoneuron output.

Changes in fusimotor activity during repetitive lengthening muscle contractions in decerebrate cats.

Responses of fusimotor neurons to lengthening vs isometric contractions have been studied in decerebrate cats. Spike discharges of fusimotor neurons to the medial gastrocnemius muscle were recorded from this muscle nerve filament during sequences of contractions and/or stretches of the lateral gastrocnemius and soleus muscles. The sequences lasted for 250-450s (duty cycle 4:2 s). Isometric contractions were elicited by electrical stimulation (40 Hz, 1.3 times motor threshold) of the muscle nerves. Lengthening contractions were elicited in the same way while the muscles were stretched by 4 mm at a velocity of 1 mm/s. Of 25 fusimotor neurons studied, 23 responded to muscle contractions with an increase in firing rate, subsiding towards the end of the sequence. The increase was either modulated with each subsequent contraction or smooth throughout the sequence. Approximately 64% of fusimotor neurons, responding to muscle contractions, responded in a similar way to the sequences of muscle stretches, applied alone. Responses to sequences of the lengthening contractions were significantly larger, on average, than those to the isometric ones, but smaller than the sum of the responses to the contractions and stretches applied separately. On the other hand, they were also larger in fusimotor units, showing no overt responses to muscle stretches alone.