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Biomedical subjects

H N Jacobson

Publications and source records attributed to H N Jacobson.

At least 19 recordsLinked to original sources

Physician attitudes toward nurse-midwives. Results of 1993 survey.

Physicians and certified nurse-midwives have worked together in hospitals, private practices, clinics and birth centers throughout Florida for over 20 years. A questionnaire was sent to all maternal health-care providers to develop an understanding of the perceived attitudes, benefits, or liabilities of the professional relationships between them. An analysis is provided of the 374 physician responses.

Attitude of Health Personnel

Infant mortality statistics do not adequately reflect the impact of short gestation.

OBJECTIVE: To determine the accuracy of National Center for Health Statistics cause-specific infant mortality data. The National Center for Health Statistics compiles these data by applying World Health Organization (WHO) selection rules to death certificate data. The WHO rules arrange medical entities into a hierarchical order and select a single underlying cause of death (ULCD). DESIGN: A comparison was made between ULCD assigned to a cohort of 335 infant death certificates by (1) a neonatologist panel, and (2) application of WHO selection rules by the Florida State Office of Vital Statistics (OVS). RESULTS: Among the 146 infants with birth weights 1500 to 4649 g, agreement between neonatologists and OVS was 88%, while among the 189 infants with birth weights 0 to 1499 g (very low birth weight), agreement was just 41%. Neonatologists selected short gestation as the underlying cause of death for 82% of very low birth weight infant records, vs 25% by OVS. Due to the application of specific WHO selection rules, OVS frequently selected immediate causes of death, such as "cardiac arrest," as the ULCD, even when the medical certifier had indicated short gestation as the ULCD. In vital statistics reports, many of these immediate causes are reported as "other respiratory conditions of newborn," or "all other perinatal conditions." CONCLUSION: WHO ULCD selection rules should be modified to allow short gestation to have a higher priority over immediate causes of infant death.

Birth Weight

Dietary standards and future developments.

The field of nutrition is in the midst of a major and rapid transition. Just how far we have come can be illustrated by the judgement that it is possible, and indeed desirable, to define multiple criteria of adequacy, multiple levels of requirement, and hence a multitiered population assessment. Moreover, in the past few years, there has also been widespread acceptance of other important concepts: no single dietary standard meets every user's needs; the quality of a diet, as well as its quantity, needs to be considered; alternative dietary standards are required and available; and finally, patterns of dietary intakes must be considered. Finally, there are fresh approaches to the relation of dietary factors and free radicals that appear to be most promising. Indeed, the issues are still unresolved, but a new definition of what RDA might mean may well emerge, along with the other evolving alternative dietary standards. The addition of a new category of naturally occurring compounds to be taken prophylactically under certain circumstances of high risk from free radicals, emphasizes the magnitude of the progress that has already been achieved.

Diet

Maternal nutrition in the 1980s.

Tight money, limited resources, and stringent accountability will characterize maternal nutrition in the 1980s. Our communities will continue to need the best available services. But those needs will have to be much better defined so that funds can be allocated more wisely. The urgency of the times requires that we assemble our baseline data on health and nutrition as rapidly as possible so that we can consolidate the achievements of the 1970s with a minimum of loss. Only then can we generate plans and expectations that fit the years ahead.

Cost-Benefit Analysis

Influence of pregnancy weight gain on the size of infants born to underweight women.

The influence of weight gain during pregnancy on duration of gestation and infant size at birth was examined among women beginning pregnancy underweight and at normal weight. Results of the review of 654 prenatal and delivery records revealed that 1) Prepregnancy weight status was not associated with the amount of weight gained during pregnancy; 2) underweight women who gained the same amount of weight as normal weight women delivered infants at a younger gestational age and of lower birth weight and length; 3) more than half the infants born to underweight women failing to gain more than 9 kg during pregnancy weighed less than 2501 g. These results suggest that recommendations for weight gain during pregnancy be based on prepregnancy weight status and that adequate weight gain is of critical importance to women beginning pregnancy underweight.

Age Factors

The repair of fractured membrane bones in the newly hatched chick.

Repair of a fractured membrane bone, the quadratojugal (QJ), has been studied in the newly hatched chick. Complete open fractures never united by bony fusion, even in birds maintained for six months post-fracture. Extraperiosteal connective tissue invaded the fracture gap and formed thick fibrous bundles which stabilised the fracture. Cartilage of two types formed on these bones. One was derived from periosteal cells and the other from osteoblasts or osteocytes. Considerably more cartilage formed in bones partially fractured than in those completely fractured. The "periosteal" cartilage did not form if the periosteum was removed at the time the bone was fractured. This was because, although the fibrous layer of the periosteum regenerated, the cambial layer did not. Metaplastic cartilage did form in the absence of the periosteum. Isolating fractured bones within polyethlene or glass tubes prevented accumulation of a blastema between the bony fragments. Cartilage did not form inside the tubes but did form where the ends of the tubes abutted onto the bones. Large defects in the bones (4 mm gaps, 4 mm of bone in the place of the QJ) healed via fibrous union with minimal osteogenesis and no chondrogenesis. Severing M. depressor mandibulae at the time the bone was fractured inhibited chondrogenesis, favoured osteogenesis and resulted in development of a pseudarthrosis. The potential for differentiation of the cells of the QJ and the role of the adjacent tissues as they related to repair of the fracture was discussed, and the ability of cells from membrane bones to become chondrogenic emphasized.

Animals