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Biomedical subjects

B Krebs

Publications and source records attributed to B Krebs.

At least 73 records · Page 4Linked to original sources
PubMed1989

Abnormal melatonin response to 5-methoxypsoralen in dementia.

The authors investigated the melatonin response to 5-methoxypsoralen in 39 healthy adult and elderly subjects and in 13 demented, 13 depressed, and 13 schizophrenic inpatients. Subjects' plasma melatonin levels were evaluated before they took single, oral 40-mg doses of 5-methoxypsoralen and 3 hours afterward. The preliminary results indicate that the melatonin response of the pineal gland to 5-methoxypsoralen is reduced in demented patients compared to that in healthy elderly subjects. Depressed and schizophrenic patients had a normal melatonin response to the drug. This finding suggests that the pineal gland may be functionally impaired in dementia but not in depression.

Adult↗
PubMed1988

Twenty-four-hour profiles of body temperature and plasma TSH in bipolar patients during depression and during remission and in normal control subjects.

The 24-hour patterns of body temperature and plasma thyrotropin (TSH) were measured in eight bipolar patients in both depressed and recovered (after 3 weeks of treatment) states and in eight normal control subjects. Clear circadian patterns were detected for both temperature and TSH. Nocturnal body temperature was increased and the nocturnal surge of TSH was blunted during depression; these abnormalities were corrected after recovery. The inverse relationship between changes in body temperature and TSH levels at night suggests that changes in thermoregulation may be responsible for the neuroendocrine disturbance and may play a role in the pathophysiology of depression.

Bipolar Disorder↗
PubMed1987

The quadriceps function in patellofemoral disorders. A radiographic and electromyographic study.

The influence of quadriceps contraction on patellar alignment was investigated in tangential views of 31 patients with patellofemoral complaints and compared with 25 controls. The congruence angle decreased significantly following quadriceps contraction in patients with patellar subluxation in contrast to those with chondromalacia and normals. Electromyography (EMG) of the vastus lateralis (VL) and vastus medialis obliquus (VMO) during maximal quadriceps contraction was obtained prior to and after 3 months of isometric quadriceps exercises in 15 knees with patellar subluxation and in 11 with idiopathic chondromalacia of the patella. The EMG after 3 months revealed an increase in the activity of both VL and VMO only in patients with patellar subluxation, but the muscular balance of the patella remained unchanged. Only seven patients were improved after 3 months. A more selective training of the VMO is proposed.

Adolescent↗
PubMed1987

Immunohistochemical distribution of the 52-kDa protein in mammary tumors: a marker associated with cell proliferation rather than with hormone responsiveness.

We have previously described a secreted glycoprotein of mol. wt 52,000 (52-kDa protein) which is induced by estrogen in some human breast cancer cell lines. This protein has been identified as the proenzyme of a lysosomal cathepsin-D-like protease which is secreted in large proportions in breast cancer cells. To determine which information may be generated by this marker when detected in mammary tumors, in comparison with hormone receptors, we used monoclonal antibodies interacting specifically with the 52-kDa protein and its related cellular processed products (mols. wts 48 and 34 kDa). A high concentration of this protein has been shown in proliferative ductal mastopathies and cysts, suggesting its value in detecting high-risk mastopathies. We now present the immunoperoxidase distribution of this protein in breast carcinoma compared to the cytosolic hormone receptors assayed in parallel. In 232 breast cancers, no correlation was found between the cellular 52-kDa protein content and cytosolic estrogen or progesterone receptor concentrations. This absence of correlation was also shown by the constitutive production of this protein by estrogen-receptor-negative breast cancer cell lines and confirmed by double immunostaining of breast cancer cell aspirates showing a dissociation between the cytoplasmic staining of this 52-kDa lysosomal protease and the nuclear staining of the estrogen receptor. These clinical results, associated with the in vitro mitogenic and proteolytic activities of this protein, strongly suggest that the 52-kDa protein staining in tissue is associated with tumor proliferation and/or invasion, rather than with hormone responsiveness.

Antibodies, Monoclonal↗
PubMed1987

5-Methoxypsoralen increases the plasma melatonin levels in humans.

The aim of this study was to evaluate the acute effects of 5-methoxypsoralen (5-MOP) on the melatonin secretion in humans. Eleven normal volunteers were investigated before (drug-free) and after 6-day periods of treatment with oral 5-MOP, first administered daily at 9 A.M. and after a 1-week free interval administered daily at 9 P.M. Under nyctohemeral conditions, the plasma melatonin levels were evaluated over a 24-h period in each session by hourly blood samples and radioimmunoassay. The sensitivity of the retina to light was also evaluated by means of electroretinography performed at 11 A.M. before and after a morning administration of 5-MOP. Plasma levels of melatonin were significantly increased from the second hour after 5-MOP administration. The hourly mean levels were significantly higher after 5-MOP administration compared to baseline values. This increased secretion was more pronounced after evening than after morning administration. Also, 5-MOP increases the sensitivity of the retina to light under photopic conditions and in the early stages of the dark adaptation period, as observed under scotopic conditions.

5-Methoxypsoralen↗
PubMed1986

Gas-producing infections after lower-limb amputation because of ischemia.

During the period 1972-1982, 22 patients with gas-producing infections after lower-limb amputation because of ischemia were reviewed. In 16 cases bacteria of the genus Clostridium could be cultured. Treatment consisted of hyperbaric oxygen, surgical debridement, and antibiotics. The incubation period was 1-11 days after the primary amputation, and the duration of the infection 2-31 days, significantly lower among 14 patients with diabetes mellitus. There was no difference in the course of clostridial and nonclostridial infections. No deaths were attributable to gas-forming infection.

Aged↗
PubMed1986

Dynamic knee brace in the treatment of patellofemoral disorders.

The efficiency of a knee brace with a 0 degree-30 degrees range of motion was studied in 17 patients with anterior knee pain. Eighteen patients with identical symptoms served as controls. The brace was worn for 6 weeks. Follow-up was performed after 6 weeks and 3 and 12 months. After 6 weeks, 82% of the patients treated with the brace were classified as improved, compared with 44% without it, according to a strict evaluation system. However, after 12 months only 35% of the patients treated with the knee brace could be rated as improved. Despite this marked deterioration, the brace should be considered an alternative to immobilization, because it minimizes the load on the patellofemoral joint and prevents atrophy of the quadriceps muscle.

Adolescent↗
PubMed1986

Patellar height and patellofemoral congruence.

The patellar tendon/patella ratio and the patellofemoral congruence was estimated in 118 knees. There was a statistically significant positive correlation between the two measurements, high-riding patella occurring with patellofemoral incongruence.

Adolescent↗
PubMed1986

Isometric contractions in the patellofemoral pain syndrome. An electromyographic study.

The role played by the vastus lateralis and vastus medialis obliquus in their alignment of the patella during maximal isometric quadriceps contractions was studied by electromyography in 28 patients with unilateral symptoms of the patellofemoral pain syndrome. Eleven knees were classified as subluxation of the patella and 17 as idiopathic chondromalacia patellae. The muscular activity pattern was the same in the two groups but decreased as compared with the contralateral nonsymptomatic knees. However, none of the groups revealed differences in the activity of vastus lateralis and vastus medialis obliquus suggesting muscular imbalance.

Adolescent↗
PubMed1986

The circadian rhythm of plasma thyrotropin in depression and recovery.

The 24-hr patterns of plasma thyrotropin have been observed in 12 endogenous depressed patients in both depressed and recovered states and in 13 normal subjects. A clear circadian rhythm was detected in controls with high values at night. In depression, the circadian rhythm was altered with amplitude reduction and blunted nocturnal secretion, abnormalities particularly relevant in bipolar patients. This flattened profile could be linked to the blunted response of TSH to TRH administration reported in depressed patients. Normal nyctohemeral patterns have been restored after recovery. These chronobiological abnormalities as well as their normalization under antidepressant drugs seem to be similar to those reported for various parameters (e.g. temperature, cortisol, etc) in depression which could support the chronobiological hypothesis for affective disorders.

Antidepressive Agents↗
PubMed1986

Patellofemoral incongruence in chondromalacia and instability of the patella.

We measured the patellofemoral congruence in tangential radiographic projections according to Merchant in 64 patients with unilateral patellar pain. The congruence angle was usually within normal limits. However, compared with the asymptomatic side, the angle was increased in chondromalacia and instability of the patella. A comparison of congruence angles of the two knees seems more valuable than a comparison with normal values.

Adolescent↗
PubMed1986

Scintimetry of hip joint tamponade in dogs.

A unilateral, continuous hip joint pressure of 50 mm Hg was established for 6 h in five puppies under general anesthesia. 99mTc-DPD scintimetry 2 and 4 weeks after tamponade showed the mean ratio between the investigated and control hip to be 1.00 and 1.01, respectively, in the epiphyses. After killing and removal of the upper femora, the same ratio was 0.94 for epiphyses and 1.02 for metaphyses. Our study did not show signs of persistent bone ischemia after tamponade below the arterial pressure.

Animals↗
PubMed1986

Alphafetoprotein and atretic follicles in the ovary of the pregnant rat.

Previous experiments have been conducted concerning the role of alphafetoprotein in genital system blockade in several cases: during adult rat N2-fluorenylacetamide hepatocarcinogenesis, after alphafetoprotein injections into normal adult female rats, during fetal life, and during postnatal and prepuberal development. In these conditions, alphafetoprotein is present at high plasma levels, and the normal cyclic ovarian function is stopped or nonexistent. The degenerating oocytes observed in the ovaries are often AFP-positive by histo-immunolocalization. Pregnancy corresponds to a physiological state in which alphafetoprotein levels are high while the gonadal activity is not characterized by ovulatory cycles. In order to assess our hypothesis, alpha-fetoprotein was studied in the ovary of pregnant rats from day 18 to 21 of gestation by an immunofluorescent technique, and alpha-fetoprotein was assayed in plasma samples. The results of this work show that, during pregnancy, follicular maturation is blocked at the antral stage, and the follicles contain degenerating oocytes that are AFP-positive in immunofluorescence. In conclusion, we suggest that the alpha-fetoprotein produced by the fetal liver and the yolk sac is disseminated in the amniotic fluid and passes through the placenta, and then reaches the ovarian follicles and the oocytes. The possible role of alphafetoprotein in follicular atresia is discussed.

Animals↗