Doppler transmitral flow velocity was measured in premature infants. The early diastolic peak velocity, the peak velocity of early diastole/peak velocity of atrial contraction ratio, and total flow velocity-time integral increased significantly with advancing gestational age and body weight. The peak filling rate normalized to stroke volume (NPFR) did not correlate with gestational age or body weight. Moreover, mean NPFR was not significantly different between premature and term infants. Thus NPFR demonstrates that changes in the left ventricular filling patterns with advancing gestational age and increasing body size are related to the progressive increase in loading conditions, rather than to sequential changes in myocardial properties.

Birth Weight↗

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Serial pulsed Doppler assessment of early left ventricular output in critically ill very low-birth-weight infants.

Serial, detailed assessments of left ventricular output (LVO) in critically ill very low-birth-weight (VLBW) infants of four different gestational ages were performed in the early neonatal period using pulsed Doppler echocardiography. Initially, the LVO values of all groups at 3 hours of age were relatively high. However, LVO dropped transiently at 12 hours and then increased again after 24 hours reaching a steady level of 160-180 ml/kg/min after 48 hours of age. In all four groups, heart rate also decreased significantly at 12 hours of age but did not increase at 24 hours of age. Both the left ventricular stroke volume and the left ventricular ejection fraction in all groups exhibited similar longitudinal changes to those observed for LVO. The LVO values observed in the lower gestational age group were significantly lower than those observed in the upper gestational group before 24 hours of age. Both patent ductus arteriosus and mechanical ventilation did not significantly influence the changes in LVO of VLBW infants at least before 36 hours of age. Our results suggest that in the early neonatal period, there are drastic changes in LVO of VLBW infants that reflect not only changes in heart rate but also changes in myocardial contractility.

Cardiac Output↗

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Serial pulsed Doppler assessment of pulmonary artery pressure in very low birth-weight infants.

We assessed pulmonary artery pressure (PAP) during the early neonatal period in very low birth-weight (VLBW) infants using serial echocardiographic measurements of the ratio of the pulmonary artery acceleration time to the right ventricular ejection time corrected by heart rate [AT:RVET(c)]. Eighty-four VLBW infants weighing less than 1,500 g were examined using serial color Doppler echocardiography from 3 hours to day 7 after birth. The AT:RVET(c) of infants born after 30 weeks of gestation showed a rapid, significant increase during the early neonatal period, whereas those of the groups born at less than 30 weeks showed no significant increase before day 14. At 24 hours after birth, the AT:RVET(c) values of VLBW infants did not correlate well with either the ratio of the right preejection period to the right ventricular ejection time on M-mode echocardiography or the pressure gradient between the right ventricle and the right atrium, as estimated by tricuspid regurgitation on pulsed Doppler echocardiography. The AT:RVET(c) value for the chronic lung disease (CLD) group did not differ significantly from that for the oxygen-dependent group at any assessment point. During the early neonatal period, the AT:RVET(c) of VLBW infants, as calculated by pulsed Doppler echocardiography, differed with their gestational age and did not appear to correlate well with PAP. Our data also suggest that AT:RVET(c) values may not be a good predictor of the subsequent occurrence of CLD in VLBW infants.

Bronchopulmonary Dysplasia↗

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Postnatal changes in left ventricular volume and contractility in healthy term infants.

To evaluate how the size of the ductus arteriosus affects neonatal left ventricular (LV) volume and contractility, we serially obtained two-dimensional and Doppler echocardiograms at 2, 12, 24, and 120 hours after birth in 20 healthy infants. LV volume was calculated by the biplanar Simpson's rule, and ductus arteriosus size with left-to-right shunting was measured by two-dimensional and Doppler echocardiography. At 2 hours, the ductus arteriosus was at its maximal size, and the LV end-diastolic volume was 1.2-fold higher than at the subsequent hours after birth. Additionally, there was a significant linear correlation between the end-diastolic volume and the ductal diameter. In contrast, the peripheral vascular resistance, derived from blood pressure measurements and Doppler echocardiography, was lowest at 2 hours of age. The mean normalized systolic ejection rate, an index of contractility, remained constant throughout the study period. These results suggest that alterations in the LV end-diastolic volume soon after birth depend on changes in ductal flow, which in turn is affected by ductal diameter, and that the neonatal left ventricle operates at its maximal performance with limited contractility during ductal patency.

Age Factors↗

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Postnatal left ventricular contractility in very low birth weight infants.

The objective of the study was to evaluate postnatal changes in left ventricular (LV) contractility in very low birth weight (VLBW) infants. An echocardiographic study comparing 18 VLBW infants without significant complications and 16 normal term infants was carried out at the Neonatal Intensive Care Unit in Akita University Medical Hospital, Japan. The echocardiographic examinations were performed within 6 hours of birth and on day 5. We obtained the relations between rate-corrected mean velocity of circumferential fiber shortening (mVcfc) and end-systolic wall stress (ESS), which were calculated from two-dimensional LV short-axis views to compensate for the distorted LV shape, and we compared these relations statistically. In both VLBW and term infants there were inverse linear correlations between mVcfc and ESS for each study period (p < 0.05). The regression line of VLBW infants had a lower y-intercept and a steeper slope than that of term infants at 6 hours of age but almost corresponded on day 5. It is concluded that the left ventricle of VLBW infants adapts to postnatal hemodynamic alterations with low contractility but operates with a contractile state similar to that of term infants on day 5.

Adaptation, Physiological↗

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Regulation of L-DOPA production by genetically modified primary fibroblasts transfected with retrovirus vector system.

Although intracerebral grafting has become established as a new strategy for the treatment of Parkinson's disease, there are many problems regarding such grafts. We focused on the grafting of primary skin fibroblasts. Rat primary skin fibroblasts were transfected with a retrovirus vector containing cDNA of human tyrosine hydroxylase (TH) type 1 (LTHSNL) or of cytomegalovirus promoter (CTHSNL) as a foreign promoter. In these genetically modified fibroblasts, L-DOPA production and release were analyzed in vitro by immunocytochemistry and high-performance liquid chromatography with electrochemical detection (HPLC-ECD). Being supplemented with the biopterin (BH4:(6R)-L-erythro-tetrahydrobiopterin) cofactors required for TH activity, these cells produced and released L-DOPA into the culture medium. When CTHSNL and BH4 were combined, L-DOPA production increased with time, regardless of the number of cell passages, or the duration of liquid nitrogen freezing. This suggests that the foreign gene (THcDNA) containing retrovirus vector integrates into the chromosomal DNA of the target cells (fibroblasts). Primary fibroblasts can be easily obtained and cultured. Thus, genetically modified primary skin fibroblasts transfected with a retrovirus vector system containing the TH cDNA may be promising grafts for transplantation and gene therapy in Parkinson's disease.

Animals↗

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Cerebellar vermis defect: a new neurological mutation in the rat.

A new neurological rat mutation showing hind-leg paralysis, cerebellar vermis defect, and cerebellar cortical dysplasia was named "cerebellar vermis defect" (CVD). Pathologically, affected animals already had a small-sized cerebellum in newborns and started to show hind-leg paralysis at approximately 14 days of age. The CVD rat was fertile in both sexes. Genetic analysis indicated that the CVD character is controlled by an autosomal recessive gene with 100% penetrance. The proposed gene symbol is Cvd.

Animals↗

PubMedDate not supplied

An individual patient comparison of response to a memory training program--psychogenic V organic amnesia: brief report.

Psychogenic amnesia ("dissociative amnesia" in DSM-IV) has received relatively little attention in the literature. We compared neuropsychological and behavioral findings between a patient with psychogenic amnesia and one with organic amnesia from their early stages in a rehabilitation program. A 52-yr-old man developed anterograde and retrograde amnesia and short-term memory disturbance 1 mo after an operation for esophageal carcinoma, with no loss of personal identity and information. No apparent organic causes were identified, but because the patient and his wife rejected psychiatric treatment and memory deficit characteristics were compatible with that of an organic origin, the patient was referred to a physiatrist. A 46-yr-old man with anterograde amnesia was diagnosed with limbic encephalitis based on findings of magnetic resonance imaging and single-photon emission computed tomography, which showed lesions in both medial temporal lobes. Both patients underwent "memory book" training because they showed preserved performance in motor learning tasks. The first patient's responses to training contrasted with the other's and were indicative of psychogenic amnesia, with cancer representing a precipitating stress. Counseled by the physiatrist, the patient and his wife accepted suggestions to undergo psychiatric treatment. We propose that it is important to consider behavioral responses to memory rehabilitation as well as neuropsychological findings in differentiating psychogenic amnesia from an organic one and that physiatrists may be pivotal in diagnosing and initiating treatment in such psychiatric disorders.

Amnesia↗

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Chronic stress evaluation using neural networks.

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Adrenal Glands↗

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Effects of high-frequency sound on electrochemical potential using the single-barrel method in guinea pigs.

There are only a few studies investigating the effects of ultrasound on hearing. This paper reports on an experimental investigation on the effect of the long-time exposure to a moderate sound pressure level, high-frequency sound of 16 kHz on the guinea pig inner ear using electrophysiological methods. A decrease of the absolute value of negative potential was observed in the endocochlear potential (EP). The effects of high-frequency sound on EP and electrochemical potential could be explained by a change in the K+ permeability of hair cells.

Acoustic Stimulation↗

PubMedDate not supplied

Effects of high-frequency sound on the guinea pig cochlea. Electrophysiological study using cochlear microphonics, action and endocochlear potential.

There are only a few studies investigating the effect of high-frequency sound on hearing. Authors investigated experimentally the effect of long exposure to high-frequency sound (19 and 25 kHz) below 100 dB (SPL) on guinea pig inner ear. Changes in cochlear microphonics (decrease of maximum output voltage) and especially in endocochlear potential (decrease of the absolute value of negative potential) were observed. The effects of high-frequency sound (10-30 kHz) on the inner ear were discussed.

Action Potentials↗

PubMedDate not supplied

Effect of 4 kHz tone exposure on the guinea pig inner ear: relation in the change of cochlear microphonics, action potential, electrochemical potential and K+ ion concentration induced by noise exposure.

Using 110 male albino guinea pigs, and applying electrophysiological methods, we investigated the effects of 4 kHz tone at moderate sound pressure level on the inner ear at different exposure times (6, 12, 24 and 48 h). Longer than 12 h exposure to 4 kHz tone had a considerable effect on the hearing, inducing a decrease in the maximum output voltage of cochlear microphonics and an increase in the K+ concentration in the endolymph.

Action Potentials↗

PubMedDate not supplied

Primary malignant lymphoma of the uterine corpus diagnosed by endometrial cytology. A case report.

BACKGROUND: A relatively small number of cases of primary malignant lymphoma of the uterine corpus have been reported, and it is rare for cases to be preoperatively diagnosed by cytology. CASE: A 59-year-old female experienced abnormal uterine bleeding of two months' duration. Preoperative evaluation of endometrial cytology revealed malignant cells. These cells demonstrated a rather round or oval configuration, with a markedly increased nuclear/cytoplasmic ratio, and were isolated and scattered in an inflammatory background. The nuclei were round or oval, and macronucleoli were marked. The cytologic diagnosis was malignant lymphoma. Postoperative histologic evaluation verified the presence of a primary malignant lymphoma in the uterine corpus, with a B-cell phenotype. CONCLUSION: Preoperative endometrial cytology correctly demonstrated malignant lymphoma of the uterine corpus.

Biopsy↗

PubMedDate not supplied

Differentiation-inducing factor-1, a morphogen of dictyostelium, induces G(1) arrest and differentiation of vascular smooth muscle cells.

Differentiation-inducing factor-1 (DIF-1) is a morphogen that induces differentiation of DICTYOSTELIUM: Recently, DIF-1 has been shown to inhibit proliferation and induce differentiation in tumor cells, although the underlying mechanisms remain unknown. In this study, we examined the effects of DIF-1 on the proliferation and differentiation of vascular smooth muscle cells, to explore novel therapeutic strategies for atherosclerosis. DIF-1 nearly completely inhibited DNA synthesis and cell division in mitogen-stimulated cells. DIF-1 inhibited the phosphorylation of the retinoblastoma protein and the activities of cyclin-dependent kinase (Cdk) 4, Cdk6, and Cdk2, which phosphorylate the retinoblastoma protein. DIF-1 strongly suppressed the expression of cyclins D1, D2, and D3, as well as those of cyclins E and A, which normally began after that of the D-type cyclins. The mRNAs for the smooth muscle myosin heavy chains SM1 and SM2 were expressed in quiescent cells in primary culture, and these expression levels decreased after mitogenic stimulation. In the presence of DIF-1, the rate of the reduction was significantly decelerated. Moreover, the addition of DIF-1 to dedifferentiated cells induced the expressions of SM1 and SM2, accompanied by a reduction in the level of SMemb, a nonmuscle-type myosin heavy chain. Therefore, DIF-1 seemed to interrupt a very early stage of G(1) probably by suppressing the expressions of the D-type cyclins. Furthermore, this compound may prevent phenotypic modulation and induce differentiation of vascular smooth muscle cells.

Cell Differentiation↗