106Ru/106Rh plaque radiotherapy for malignant melanomas of the choroid

Therapeutic results are presented with follow-up examinations of at least 5 years (min. 5 years, max. 22 years) after ¹⁰⁶Ru/¹⁰⁶Rh plaque radiotherapy of posterior uveal melanomas. Out of 227 patients 146 (= 64.3%) could be treated successfully, 37 (= 16.3%) had to be enucleated and are alive, 44 (= 19.4%) died from metastases and 40 (17.6%) from other causes. 75.0% of all small melanomas (T1a) showed an excellent regression pattern to flat scars. Five years after treatment the survival rate was 83.7% (deaths from any causes) respectively 88.2% (deaths from metastases only) and 64.8% (deaths from any causes) respectively 79.7% (deaths from metastases only) ten years after irradiation. ¹⁰⁶Ru/¹⁰⁶Rh plaque radiotherapy can be recommended for small (Tla, b) and medium sized (T2) choroidal melanomas.     

Exteroceptive suppression periods in jaw-closing muscles. Variability and relation to experimental pain and sustained muscle contraction

The duration of the late exteroceptive suppression period (ES₂) of temporal muscle EMG activity has been reported to be reduced in patients suffering from chronic tension-type headache. Methods of recording and analysing ES₂ have varied between centers and reproducibility of results within subjects , although insufficiently studied, has generally been poor. ES₂ was investigated in 30 healthy subjects, using a computerized technique of recording, rectifying and averaging the EMG signals. Hour to hour and week to week variations of ES₂ durations were calculated, and the influence of pain during a cold pressor test and of sustained muscle contraction on ES₂ durations was investigated. The intra-individual variation of ES₂ durations was 16.0% from hour to hour and 20.7% from week to week. The inter-individual variation was 36.7%. The present method for analysis of ES₂ periods proved to be reliable, as the intra-observer variation was 4.2% and the inter-observer variation 4.6%. ES₂ periods were significantly shorter on the first compared to the second day of examination ( p = 0.006) and during experimental pain ( p = 0.0005). We recommend the use of the computerized averaging technique in future studies and caution against the dependence of results upon factors such as conditioning and pain.     

Surgical management of endocrine tumor of the pancreas in Japan

Endocrine tumor of the pancreas is potentially malignant. A multicenter analysis of these tumors was conducted to clarity the present status of their surgical management and the subsequent long-term surgical results. The Japan pancreatoduodenectomy (JPD) study group carried out the study; 368 patients were enrolled and variables related to tumor characteristics, surgery, and survival were retrospectively analyzed. There were 222 patients with functioning tumor and 143 patients with nonfunctioning tumor. Malignant tumor was found in 140 of 368 (38%) of the patients, and 63/140 (45%) of these patients had metastatic lesion; the most common site of the metastasis was liver 34/136 (25%), followed by regional lymph nodes 26/136 (19%). Pancreatic resection was performed in 91% of patients with nonfunctional tumor and in 83% of those with malignant tumor, and 73% of the pancreatic resections were done with lymph node dissection. The overall 5-year actuarial survival rate was 76% in patients with malignant tumor. The actuarial 5-year survival rate was 93% in the patients without metastasis and 83% in patients who received curative resection. Multivariate analysis showed that the presence or absence of synchronous metastasis was the sole significant prognostic factor. The results suggest that: (i) malignant endocrine tumor of the pancreas is a curable malignancy when pancreatic resection with lymph node dissection is adopted and (ii) that synchronous metastasis is the dominant prognostic factor. This study was carried out as a group project. The authors' institutions are as follows     

Survival of low birthweight infants in central Queensland

The survival of low birthweight infants £2000g born in the central Queensland area during the years 1979 to 1991 was examined. Five hundred and sixty such infants were either delivered at one of the two Rockhampton obstetric units (Rockhampton Base Hospital and the Mater Misericordiae Hospital) or retrieved from outlying central Queensland areas. Both hospitals had intensive care nurseries capable of ventilation and infants were transferred to tertiary centres only for cardiac or surgical treatment. The study involved all liveborn infants', including those with lethal malformations and all deaths up to the time of discharge. Survival rates were as follows: £500 g 0%, 501 £750 g 30%, 751 £1000 g 51%, 1001 ± 1500 g 79%, 1501 £2000g 93%. The survival of Aboriginal infants and outborn infants were found to be essentially the same as the overall group.     

Free vascularized jejunum interposition for pharyngoesophageal reconstruction after total laryngopharyngectomy

The records of 28 patients who underwent free jejunal graft reconstruction after resection for cancer involving the pharynx were analysed. Seven patients had a T₃ carcinoma, 15 patients T₄ and six patients recurrence after laryngectomy. Ten patients had received radiotherapy in the past. Post-operatively, 15 patients (54%) had complications and two patients (7%) died. No significant difference was observed in the complication rate between the group that received radiotherapy in the past and those who did not. Nineteen patients received post-operative radiotherapy. Nine patients had no radiotherapy on the basis of complete resection or because of serious complications. For the whole group the 2-year recurrence free period and survival were 42% and 51% respectively. The postoperative radiotherapy group had a significantly better survival (73%) and recurrence free period (63%) than the group without post-operative radiotherapy (0%). Thus, post-operative radiotherapy seems indicated irrespective of resection margins.     

Ten-year stability of cardiovascular responses to laboratory stressors

In this study we examined test-retest stability of cardiovascular stress responses over a decade of the life span. Participants were 55 male college undergraduates. 19 years of age at initial testing, and 29 years of age at follow-up testing Stressors were a foot cold pressor and an aversive reaction time task. Cardiovascular measures included systolic and diastolic blood pressure, heart rate, and preejection period. For cold pressor, the magnitude and pattern of cardiovascular responses remained unchanged at the 10-year follow-up. For the reaction time task, the characteristic cardiovascular response patterns was preserved but with significant attenuation of magnitude. The present findings are consistent with previous observations of temporal stability but over a substantially longer test-retest interval. The long-term stability of stress responses is discussed in the context of stress test methodology, behavioral response demands, and maturation of the physiological systems involved in cardiovascular response expression.     

Rising mortality from motor neurone disease in Sweden 1961–1990: the relative role of increased population life expectancy and environmental factors

Recent studies of mortality from motor neurone disease (MND) in Sweden have demonstrated rising levels of mortality from the disease, especially amongst older age groups. Case-control investigations have suggested that certain environmental factors are significantly related to variations in mortality from the disease, and are associated with a probable individual susceptibility to MND. This study applies an innovative epidemiological technique to longitudinal and cohort analysis of Swedish mortality from MND during the period 1961 to 1990. Survival modelling shows that a subpopulation susceptible to MND exists in Sweden, as has been demonstrated in other countries. The increased life expectancy of the Swedish population since 1961 has resulted in more of that susceptible population living to the ages at which MND is expressed, explaining the majority of the increase in mortality from the disease. However, environmental factors may play a role in accelerating the course of MND and may affect the timing of death within the susceptible sub-population.     

Excitability properties of medial forebrain bundle axons of A9 and A10 dopamine cells

A9 and A10 units identified as dopaminergic were recorded with extracellular micropipettes. The units were antidromically activated by electrical stimulation at the level of the preoptic area. The absolute refractory periods ranged from 1.2 to 2.5 ms. During the 2–8 ms of the relative refractory period, conduction was slower than normal by up to 1.5 ms. The time constant, C, of the strength-duration curve ranged from 0.4 to 0.6 ms. The current (I)-distance (D) relationship, tested by moving the stimulating electrode past the axon, was approximately parabolic (I = K D exp 2), with the constant of the equation, K, ranging from 900 to 2000 μA/mm exp 2, for 0.5 ms pulses. This relationship allows calculation of the radius of the field of dopamine axon excitation at any current. These high K values show that axons of dopamine cells cannot be activated unless high current densities are derivered, even when electrodes are placed near the axons. These data allow determination of the extent to which dopamine axons can be the directly activated substrates for behaviors, such as self-stimulation and circling, which are evoked by electrical stimulation of the medial forebrain bundle or internal capsule.