PubMed Health⌕ Search

Biomedical subjects

L Perbeck

Publications and source records attributed to L Perbeck.

At least 19 recordsLinked to original sources
PubMed1998

Presence of thyrotropin receptor in infant adipocytes.

In healthy infants, the levels of TSH are known to peak at 50-100 times adult values during the first days of life. In studies of isolated human infant adipocytes, we have earlier shown that bovine TSH (bTSH) has a strong lipolytic effect, accompanied by a blunted response of adipocytes to catecholamines. In this study, we used human recombinant TSH (hTSH), and incubation of adipocytes with hTSH induced a lipolytic response similar to that obtained with the beta-adrenergic receptor agonist isoprenaline in adipocytes isolated from three infants. The lipolytic effect of hTSH was completely blocked by inhibitory TSH receptor (TSHR) antibodies. The TSHR mediates the effects of TSH in the thyroid, and it has been detected in some extrathyroid tissues, but not in isolated human adipocytes or childhood adipose tissue. In this study, we found TSHR RNA in infant and adult adipose tissues and isolated adipocytes with reverse transcriptase-PCR. The sequence of the amplified PCR product agreed with the published sequence. Northern blot hybridization on RNA prepared from infant adipose tissue showed a transcript of the expected size, and the expression of TSHR seemed higher in infant than in adult adipose tissue. In conclusion, this study indicates that TSH plays an active role in the metabolic adaptation after birth.

Adipocytes↗
PubMed1997

Touch sensibility in the breast after subcutaneous mastectomy and immediate reconstruction with a prosthesis.

Touch sensibility was assessed with von Frey's monofilaments in the breasts of 10 healthy women (controls) and of 80 women with breast cancer who at least 1 year previously had undergone subcutaneous mastectomy and immediate reconstruction with a prosthesis. Touch thresholds were measured at nine positions on each breast. Low threshold values (< 3.2 mN) and good reproducibility were found in the controls. In the patients' surgically treated breasts normal (< 3.2 mN) or subnormal (< 20 mN) median threshold values were found outside the areola. Higher median values were noted on the areola and nipple; on the nipple, however, one third of the patients had normal sensibility while 14% lacked sensibility. The only factors found to influence the results were simultaneous subcutaneous reduction mammaplasty (lower touch thresholds) and the localisation of the incision (slightly lower thresholds for lazy-S than inframammary incision). These results confirm the clinical impression that touch sensibility is substantially retained after subcutaneous mastectomy and immediate reconstruction with a prosthesis.

Aged↗
PubMed1997

Diagnostic accuracy of mammography and contrast-enhanced MR imaging in 238 histologically verified breast lesions.

PURPOSE: To determine the sensitivity and specificity of X-ray mammography and of MR imaging in 238 consecutively operated breasts, and to correlate the findings to histopathological diagnosis. MATERIAL AND METHODS: Over 15 months, 220 patients scheduled for breast surgery were examined consecutively, before surgery, by means of both mammography and MR imaging. Of the 220 patients, 18 underwent bilateral breast surgery. The entire breast was examined by means of T1-weighted transversal images using a 3D fast low-angle shot (FLASH) sequence. One pre- and 2 post-contrast scans were performed. Each breast was examined by means of mammography and 3 views were applied as routine. All palpable and mammographically suspect lesions were examined on additional images as microfocus magnification or spot compression. The two methods were evaluated independently of each other. RESULTS: In total, 145 malignant and 93 benign lesions were found at histopathological examination. The sensitivity of mammography was 89% and MR imaging 92%. The specificity was 72% in both methods. When the results of the 2 methods were combined, a sensitivity of 99% and a specificity of 55% was achieved. CONCLUSION: Mammography and MR imaging seemed to complement each other to produce a high sensitivity. Unfortunately it is impossible at present to supplement mammography with MR imaging in each patient as a routine owing to the current technical and financial limitations.

Breast↗
PubMed1996

Sensitivity and specificity of MR mammography with histopathological correlation in 250 breasts.

PURPOSE: The aim of our prospective study was to determine the diagnostic accuracy of MR mammography (MRM) in detecting malignant disease. MATERIAL AND METHODS: In 231 consecutive patients scheduled for surgery because of mammographic or palpable lesions suspected of malignancy, the breasts were examined with T1-weighted transversal images using a 3-D fast low angle shot (FLASH) sequence. One pre- and 2 post-contrast images were obtained. Histological examination of the surgical specimens showed carcinoma in 155 breasts, of which 138 were invasive and 17 in situ. RESULTS: MRM detected 144 of the 155 malignancies and was false-negative in 11 cases. Eight of these MRM-missed tumours were invasive and 3 were in situ cancers. Benign lesions were found at microscopy in 95 breasts, of which MRM correctly diagnosed 69. The cellular composition of the 26 false-positive lesions (myxomatous stromal change, high vascularity, and epithelial or apocrine hyperplasia) might explain the false positivity. The sensitivity and specificity of MRM were 93% and 73% respectively. CONCLUSION: MRM should be interpreted with caution, and supplemented with e.g. mammography and ultrasonography.

Breast Neoplasms↗
PubMed1995

Contrast-enhanced MR imaging of the breast in patients with breast implants after cancer surgery.

The purpose of the study was to determine the value of contrast-enhanced MR imaging in the assessment of local recurrence in breast cancer patients who underwent mastectomy and breast reconstruction with an implant. Eighty-three patients have been evaluated by semidynamic contrast-enhanced MR imaging. The T1-weighted FLASH 3-D sequence was repeated twice postcontrast for evaluation of the entire breast bilaterally. The findings were compared to physical examination, mammography and histopathology. Recurrence verified by histopathology occurred in 14 of 83 patients (17%). Contrast-enhanced MR imaging was superior to palpation and mammography in revealing recurrences, especially when these were located close to the chest wall. MR was also more sensitive in detecting multiple foci of cancers. Our study revealed that MR imaging was influenced by size, type and composition of the tumor, as illustrated by the false-negative results. Therefore, the use of all 3 investigation methods is necessary for detecting recurrence at an early stage during the postoperative follow-up.

Breast↗
PubMed1994

Effect of exposure to heat and intake of ethanol on the skin circulation and temperature in ischaemic limbs.

The question of whether alcohol intake increases skin circulation is controversial. The study described here was undertaken to examine the effect on skin circulation and skin temperature in ischaemic limbs of exposure to external heat, and of alcohol intake together with such exposure. Fourteen patients with occlusive arterial disease, mean age of 65 years (range 47-80), underwent measurements of blood flow by laser Doppler flowmetry (LDF) and of skin temperature 1-2 days before and 8-10 days after vascular reconstruction. LDF and skin temperature were measured in the plantar region of the mid-forefoot with the subject supine. After 30 min of exposure to external heat, the measurements were repeated. Each subject then drank 15 ml of 50% alcohol and after a further 30 min of heat exposure the same measurements were performed again. Similarly, fourteen healthy subjects, mean age 33 years (range 21-43), were studied. In the patients there was no increase in skin blood flow or skin temperature after heat exposure alone or after combined heat exposure and alcohol intake, either before or after vascular reconstruction. In the healthy subjects LDF showed a 126% increase (P < 0.01) in skin blood flow after 30 min of exposure to external heat and a further increase by 81% after alcohol intake and an additional 30 min of heat exposure (P < 0.01). The corresponding increases in skin temperature were 3.0 degrees C (P < 0.05) and 2.9 degrees C (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Skin microcirculatory and thermal changes in elderly subjects with early stage of pressure sores.

Elderly subjects are prone to develop pressure sores over the sacrum area mainly due to external pressure and shear effects which negatively affect the skin microcirculation. The aim of the study described here was to measure skin microcirculatory and thermal changes in twelve elderly patients with an early stage of pressure sore and in ten elderly subjects without pressure sore. The total skin microcirculation at a damaged risk area, the sacrum, and a reference area of undamaged skin over the gluteal region, was evaluated using the laser Doppler fluxmetry. The nutritive transport of small solutes, characterized by the transcapillary exchange of sodium fluorescein, was evaluated using the fluorescein flowmetry technique. The skin temperature was measured with a thermoelement. The skin microcirculation at the area with an early stage of pressure sore was significantly higher than at undamaged skin as measured by both techniques. The total microcirculatory blood flow increased > 16 times (P < 0.001) and the nutritive transport approximately 5 times (P < 0.01) compared to the reference value, and the calculated blood flow of subpapillary tissue layers increased 17-19 times (P < 0.001). However, the skin temperatures in damaged and undamaged skin did not differ significantly. These results show an increased skin microcirculation in the early stage of pressure sores but no increase in skin temperature. The more strongly increased skin blood flow in subpapillary tissue layers effectively conducts away the heat caused by the damage and the increased metabolic activity.

Aged↗
PubMed1993

Reoperation for suspected primary hyperparathyroidism.

A retrospective analysis of 93 patients undergoing 128 re-explorations for persistent or recurrent hypercalcaemia is presented. Seventy-six patients (82 per cent) became normocalcaemic after between one and five reoperations. Nine patients had hypercalcaemia caused by sarcoidosis, familial hypocalciuric hypercalcaemia or metastatic disease, and two had parathyroid carcinoma. Fifteen patients (16 per cent) developed permanent hypoparathyroidism requiring vitamin D and/or calcium therapy and nine had permanent recurrent laryngeal nerve paralysis. Undetected adenomas (41 cases) and inadequate resection in hyperplastic disease (28) were the predominant causes of initial failure. Reoperation for persistent or recurrent hyperparathyroidism restored normocalcaemia in the majority of patients. This 'cure' was achieved at the cost of considerable morbidity and a careful risk-benefit analysis of each patient is recommended before performing reoperative parathyroid surgery.

Adenoma↗
PubMed1993

Changes in skin blood flow in ischaemic limbs after vascular reconstruction measured by fluorescein flowmetry and laser Doppler flowmetry.

It is not known to what extent the skin blood flow increases after vascular reconstruction in ischaemic limbs. Thus, a study was undertaken to measure skin blood flow, using the two techniques laser Doppler flowmetry and fluorescein flowmetry, before and after vascular reconstruction. The skin temperature was measured also. The plantar circulation was assessed in 14 patients (9 non-diabetics and 5 diabetics; mean age 65 years; range 47-80), with the patient in the supine position, 1-2 days before and 8-10 days after surgery. After vascular reconstruction the skin blood flow increased by 240% (P < 0.01) when measured by fluorescein flowmetry and by 148% (P < 0.01) when measured by laser Doppler flowmetry, and the skin temperature rose by 3.2 degrees C (P < 0.01). In the contralateral non-operated limb there was no significant change in skin blood flow as measured by the two methods. The results imply that after vascular reconstruction in ischaemic limbs the skin blood flow increases both in the superficial layer as determined by fluorescein flowmetry (which measures the blood flow down to 0.6 mm) and in deeper layers as determined by laser Doppler flowmetry (which measures flux down to 6 mm).

Adult↗
PubMed1992

The effect of weight-bearing pressure on the plantar circulation in diabetes mellitus.

Patients with diabetic neuropathy are prone to ulceration on the sole of the foot, especially in areas with high weight-bearing pressure. The relationship between weight-bearing pressure and nutritive skin circulation in the plantar region was studied. Gait analysis was performed with the EMED Gait Analysis System and the skin circulation was measured by fluorescein flowmetry in ten neuropathic diabetic patients and in eight healthy controls. The critical plantar foot pressure above which nutritional blood flow in the skin was arrested was 3 N cm-2 or more in both diabetic and control subjects. Below 3 N cm-2 the blood flow was independent of weight-bearing pressure both in diabetic and control subjects (correlation coefficient r = -0.01 and -0.19, respectively). Thus, our results indicate that the nutritional blood flow in the plantar region is not decreased in patients with diabetic neuropathy.

Adult↗
PubMed1992

The circulation in the nipple-areola complex following subcutaneous mastectomy in breast cancer.

To evaluate the decrease in circulation in the nipple-areola complex after subcutaneous mastectomy and immediate implantation of a submuscular prosthesis, the blood flow was studied by both fluorescein flowmetry and laser Doppler flowmetry in 24 patients with invasive breast cancer. In 14 patients a lazy-S-shaped horizontal lateral incision was used, and 10 underwent a subcutaneous reduction mammaplasty. After subcutaneous mastectomy with a lazy-S incision there was no significant decrease in blood flow in the nipple-areola complex compared with that in the untreated contralateral breast. In the breasts in which reduction mammaplasty had been done, the blood flow was reduced by 74% as measured by fluorescein (p less than 0.01), and 70% by laser Doppler flowmetry (p less than 0.05), compared with the contralateral breast. Five patients had partial or complete epidermal, and one patient had total dermal, necrosis of the complex, but there was no deep necrosis. No fluorescence was seen within the areas in which necrosis later developed in any of these six cases. The laser Doppler signal in the corresponding areas, however, was not reduced. The results show that the circulation in the nipple-areola complex is reduced more after subcutaneous reduction mammaplasty than after subcutaneous mastectomy with a lazy-S incision.

Adult↗
PubMed1992

Hyperparathyroidism associated with treatment of manic-depressive disorders by lithium.

OBJECTIVE: To clarify the association between treatment of affective psychiatric disorders with lithium, and the development of secondary hyperparathyroidism. DESIGN: Retrospective review of medical records, 1973-89. SUBJECTS: 17 patients with affective psychiatric disorders who were treated with lithium (n = 6) or with tricyclic antidepressant, or neuroleptic, drugs (n = 11) all of whom were operated on for hyperparathyroidism. MAIN OUTCOME MEASURE: Duration of lithium therapy and parathyroid histology. RESULTS: Parathyroid hyperplasia was present in 5 patients who had taken lithium during a median period of 13 years. A parathyroid adenoma was found in one patient treated with lithium for three years. Ten of the 11 patients who had been treated with tricyclic antidepressant, or neuroleptic drugs had a parathyroid adenoma and the remaining one had an adenoma as an underlying cause of hyperparathyroidism. CONCLUSION: Hyperparathyroidism in patients who have undergone long term treatment with lithium is associated with parathyroid hyperplasia. This indicates that lithium may exert a chronic stimulus that results in secondary hyperparathyroidism.

Adenoma↗
PubMed1991

Routine examination of the vocal cords before and after thyroid and parathyroid surgery.

A prospective study of the value of routine examination of the vocal cords in 239 patients before and after thyroid or parathyroid surgery is presented. From the patient's history and voice the surgeon assessed before and after operation whether vocal cord examination was necessary or not. The surgeon's judgement was compared with the phoniatrician's report. All except one of the documented recurrent laryngeal nerve palsies were suspected by the surgeon. No additional important clinical information was gained by the laryngologist's examinations. Routine vocal cord examination in connection with thyroid and parathyroid surgery is probably not necessary.

Adolescent↗
PubMed1991

Skin circulation in the nipple after reduction mammaplasty with a bipedicle vertical dermal flap.

Necrosis of the nipple after a reduction mammaplasty with transposition of the nipple is a serious complication. A study was undertaken to measure the skin circulation in the nipple before, during and after this operation. In 16 patients undergoing reduction mammaplasty according to the method of McKissock, the skin circulation was measured in both breasts by laser Doppler flowmetry (LDF) and fluorescein flowmetry (FF). LDF showed that the skin circulation increased after de-epithelialization to 245.7 +/- 39.3% of the preoperative blood flow (100%) (mean +/- SEM, p less than 0.01). When 40 ml of 0.25% adrenaline was injected into the incision lines, the corresponding increase in blood flow was 153.4 +/- 15.6% (p less than 0.01). After the medical and lateral glandular resections the blood flow in the nipple of the vertical dermal pedicle was 125.6 +/- 21.2% of the preoperative blood flow and when adrenaline was given the corresponding value was 79.3 +/- 6.5%. After the skin had been sutured, the blood flow was 128.4 +/- 25.9% of the preoperative value and in the breast in which adrenaline was injected it was 177 +/- 96.9%. One to four days postoperatively the blood flow was 123.1 +/- 19.9% of the preoperative value and in the breast that received adrenaline 130 +/- 24%. At FF homogeneous fluorescence was observed in the nipple postoperatively in all patients but one; in this patient avascular necrosis later developed. Our results thus show that the circulation in the nipple after reduction mammaplasty by the McKissock method is adequate.

Adult↗