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Biomedical subjects

M Bock

Publications and source records attributed to M Bock.

9 recordsLinked to original sources
PubMed1992

Spinal fractures during fluoride therapy for osteoporosis: relationship to spinal bone density.

Recent studies report that fluoride therapy for osteoporosis increases spinal bone density without improving vertebral fracture rate, challenging the notion that restoration of bone mass improves bone fragility. To further evaluate this issue, the relationship between spinal bone density and vertebral fracture rate was examined in a large number of fluoride-treated, osteoporotic patients. A retrospective assessment was made of clinical data collected from our observations of 389 osteoporotics treated with fluoride 30 +/- 8 mg/day (mean +/- SD) (equivalent to 66 +/- 17 mg NaF/day) and calcium 1500 mg/day for 28 +/- 18 months. Fracture rate and bone density were assessed in the same region of the spine (i.e., T12 through L4) using quantitative computed tomography (QCT). Spinal bone density increased with time on fluoride, but the relationship was hyperbolic (r = 0.99, p less than 0.0001; asymptote = 167 mg/cc on double-reciprocal plot), suggesting a plateau in the response. The spinal fracture rate decreased as a function of time on therapy (r = -0.83, p less than 0.01), and was inversely related to spinal bone density during fluoride therapy (r = 0.70, p less than 0.001 on arithmetic plot; r = -0.79, p less than 0.001 on semi-log plot). The subgroup of patients who responded to treatment with a significant increase in spinal bone density had a 48% reduction in spinal fracture rate compared with non-responders (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Hip mineral density in females with a recent hip fracture.

To evaluate the role of local bone mineral density (BMD) in the etiology of hip fractures, we measured the hip BMD using dual photon absorptiometry in 29 females who had recently suffered a hip fracture associated with minimal or moderate, but not major, trauma and compared their BMD to those of 14 young normal females, 58 early postmenopausal normal females, 13 age-matched normal females, and 114 spinal osteoporotic females without a hip fracture. Hip-fractured patients had a BMD significantly lower (P less than 0.001) than that of all other studied groups, suggesting that a low hip BMD is associated with hip fracture risk. A femoral neck BMD below 0.75 g/cm2 suggests an increased likelihood for developing a hip fracture. Peak BMD was measured at 1.03 g/cm2, a value comparable to published normative data. Thus, a loss in hip BMD of approximately 30% from peak mineral density appears necessary before a hip fracture may occur after moderate trauma.

Adult↗
PubMed1992

Cell-targeted 114Inm and drug (BCNU) combination therapy in a rat acute lymphoblastic leukaemia.

A proportion of syngeneic female rats inoculated intramuscularly with a lethal T-cell lymphoblastic (Roser) leukaemia are cured by a single intraperitoneal injection of bischloroethylnitrosourea (BCNU) (Carmustine) (10 mg kg-1) given towards the end of the preleukaemic phase (day 7). Additional therapy on day 4, using intravenous leukaemia cells lethally labelled with the radionuclide 114Inm, enhanced the overall cure rate by 30%. The spleen is a major site of indium concentration from the targeting cells so that the continuous local radiation field appears to result in a substantial reduction of the body load of leukaemia cells in the enlarged spleen particularly, thus enhancing the curative potential of the drug. The results demonstrate in principle that in patients in remission a single dose of targeted radiotherapy in the spleen combined sequentially with an appropriate drug might provide considerable aid in eliminating a residual population of leukaemia cells.

Animals↗
PubMed1977

[One year experiences with a new atrial lead (j-version) in 53 patients (author's transl)].

The new atrial leads (J-version) of type Medtronic 6991, of which we implanted endocardially a total of 53 between April 1975 and May 1976, are characterized by properties, as, up to now, were exclusively to be seen in the so-called flange electrodes of ventricular position. 1. The tined J-leads were easily to introduce and required only an average of 5 minutes to position into the right appendage. 2. Moreover, these atrial leads guaranteed an anatomic stable anchorage with a dislodgement ratio of less than 6% (3 of 53). 3. Additionally, the action voltages sensed the J-shaped electrodes showed themselves averaging 5.2 mV of very high amplitude. Up to this time comparable results could not be achieved neither by other atrial leads nor techniques of their emplacement. The intraatrial voltage thresholds exceeded, as described before, the intraventricular ones by two to three times. In spite of this, no exit block was seen in 34 cases with atrial pacing systems, not even during an observation time of maximal 13 months. Therefore, the tined J-leads fulfill all requirements of a suitable atrial electrode.

Aged↗
PubMed1975

[Action of fomocaine on heart and circulation (author's transl)].

Fomocaine shows antiarrhythmic properties. It prolongs the periods of the ECG (anaesthetized cats) and the functional refractory period (left atria of guinea-pigs, electrically driven). Effects on these parameters are qualitatively the same as with quinidine. Quantitatively fomocaine prolongs the functional refractory period in the same, the PQ-interval to a greater extent than does quinidine. In contrast quinidine has a greater effect on QRS- and QT-interval. Up to higher doses fomocaine's efficacy on contractility (dp/dtmax) and blood pressure is opposite to quinidine because they are increased by fomocaine and decreased by quinidine. The lack of toxic ECG-signs prior to lethal dosis makes fomocaine dangerous in overdosage.

Animals↗